Catalytic farming: reaction rotation extends catalyst performance

The use of heterogeneous catalysis has key advantages compared to its homogeneous counterpart, such as easy catalyst separation and reusability. However, one of the main challenges is to ensure good performance after the first catalytic cycles. Active catalytic species can be inactivated during the catalytic process leading to reduced catalytic efficiency, and with that loss of the advantages of heterogeneous catalysis. Here we present an innovative approach in order to extend the catalyst lifetime based on the crop rotation system used in agriculture. The catalyst of choice to illustrate this strategy, Pd@TiO2, is used in alternating different catalytic reactions, which reactivate the catalyst surface, thus extending the reusability of the material, and preserving its selectivity and efficiency. As a proof of concept, different organic reactions were selected and catalyzed by the same catalytic material during target molecule rotation

Perylene-Grafted Silicas: Mechanistic Study and Applications in Heterogeneous Photoredox Catalysis

This is the peer reviewed version of the following article: Chem. Eur. J. 2019, 25, 14928 14934, which has been published in final form at https://doi.org/10.1002/chem.201903539. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving[EN] A mechanistic study is herein presented for the use of heterogeneous photocatalysts based on perylene moieties. First, the successful immobilization of perylene diimides (PDI) on silica matrices is demonstrated, including their full characterization by means of electronic microscopy, surface area measurements, powder XRD, thermogravimetric analysis, and FTIR, Si-29 and C-13 solid-state NMR, fluorescence, and diffuse reflectance spectroscopies. Then, the photoredox activity of the material was tested by using two model reactions, alkene oxidation and 4-nitrobenzylbromide reduction, and mechanistic studies were performed. The mechanistic insights into their photoredox activity show they have promising dual photocatalytic activity for both organic oxidations and reductions.This work was supported by the Natural Sciences and Engineering Research Council of Canada and the Canada Foundation for Innovation. The authors are grateful to Prof. J.C. Scaiano for his generous support.Carrillo, AI.; Elhage, A.; Marín García, ML.; Lanterna, AE. (2019). Perylene-Grafted Silicas: Mechanistic Study and Applications in Heterogeneous Photoredox Catalysis. Chemistry - A European Journal. 25(65):14928-14934. https://doi.org/10.1002/chem.201903539S14928149342565Marzo, L., Pagire, S. K., Reiser, O., & König, B. (2018). Visible-Light Photocatalysis: Does It Make a Difference in Organic Synthesis? Angewandte Chemie International Edition, 57(32), 10034-10072. doi:10.1002/anie.201709766Marzo, L., Pagire, S. K., Reiser, O., & König, B. (2018). Photokatalyse mit sichtbarem Licht: Welche Bedeutung hat sie für die organische Synthese? Angewandte Chemie, 130(32), 10188-10228. doi:10.1002/ange.201709766Miranda, M. A., & Marin, M. L. (2017). Photocatalytic functionalization for the synthesis of drugs and analogs. Current Opinion in Green and Sustainable Chemistry, 6, 139-149. doi:10.1016/j.cogsc.2017.05.001Yoon, T. P. (2016). Photochemical Stereocontrol Using Tandem Photoredox–Chiral Lewis Acid Catalysis. Accounts of Chemical Research, 49(10), 2307-2315. doi:10.1021/acs.accounts.6b00280Pitre, S. P., McTiernan, C. D., & Scaiano, J. C. (2016). Understanding the Kinetics and Spectroscopy of Photoredox Catalysis and Transition-Metal-Free Alternatives. Accounts of Chemical Research, 49(6), 1320-1330. doi:10.1021/acs.accounts.6b00012Lang, X., Chen, X., & Zhao, J. (2014). Heterogeneous visible light photocatalysis for selective organic transformations. Chem. Soc. Rev., 43(1), 473-486. doi:10.1039/c3cs60188aSchultz, D. M., & Yoon, T. P. (2014). Solar Synthesis: Prospects in Visible Light Photocatalysis. Science, 343(6174), 1239176-1239176. doi:10.1126/science.1239176Prier, C. K., Rankic, D. A., & MacMillan, D. W. C. (2013). Visible Light Photoredox Catalysis with Transition Metal Complexes: Applications in Organic Synthesis. Chemical Reviews, 113(7), 5322-5363. doi:10.1021/cr300503rNarayanam, J. M. R., & Stephenson, C. R. J. (2011). Visible light photoredox catalysis: applications in organic synthesis. Chem. Soc. Rev., 40(1), 102-113. doi:10.1039/b913880nSarina, S., Waclawik, E. R., & Zhu, H. (2013). Photocatalysis on supported gold and silver nanoparticles under ultraviolet and visible light irradiation. Green Chemistry, 15(7), 1814. doi:10.1039/c3gc40450aQu, Y., & Duan, X. (2013). Progress, challenge and perspective of heterogeneous photocatalysts. Chem. Soc. Rev., 42(7), 2568-2580. doi:10.1039/c2cs35355eJiang, J.-X., Li, Y., Wu, X., Xiao, J., Adams, D. J., & Cooper, A. I. (2013). Conjugated Microporous Polymers with Rose Bengal Dye for Highly Efficient Heterogeneous Organo-Photocatalysis. Macromolecules, 46(22), 8779-8783. doi:10.1021/ma402104hFox, M. A., & Dulay, M. T. (1993). Heterogeneous photocatalysis. Chemical Reviews, 93(1), 341-357. doi:10.1021/cr00017a016Sun, H., Wang, L., Wang, Y., & Guo, X. (2018). Imide‐Functionalized Polymer Semiconductors. Chemistry – A European Journal, 25(1), 87-105. doi:10.1002/chem.201803605Nowak-Król, A., Shoyama, K., Stolte, M., & Würthner, F. (2018). Naphthalene and perylene diimides – better alternatives to fullerenes for organic electronics? Chemical Communications, 54(98), 13763-13772. doi:10.1039/c8cc07640eArzoumanian, E., Ronzani, F., Trivella, A., Oliveros, E., Sarakha, M., Richard, C., … Lacombe, S. (2013). Transparent Organosilica Photocatalysts Activated by Visible Light: Photophysical and Oxidative Properties at the Gas–Solid Interface. ACS Applied Materials & Interfaces, 6(1), 275-288. doi:10.1021/am404175yMathew, S., & Imahori, H. (2011). Tunable, strongly-donating perylene photosensitizers for dye-sensitized solar cells. Journal of Materials Chemistry, 21(20), 7166. doi:10.1039/c1jm10993fWu, Y., Zhen, Y., Ma, Y., Zheng, R., Wang, Z., & Fu, H. (2010). Exceptional Intersystem Crossing in Di(perylene bisimide)s: A Structural Platform toward Photosensitizers for Singlet Oxygen Generation. The Journal of Physical Chemistry Letters, 1(17), 2499-2502. doi:10.1021/jz1008328Würthner, F. (2004). Perylene bisimide dyes as versatile building blocks for functional supramolecular architectures. Chem. Commun., (14), 1564-1579. doi:10.1039/b401630kFerrere, S., & Gregg, B. A. (2002). New perylenes for dye sensitization of TiO2. New Journal of Chemistry, 26(9), 1155-1160. doi:10.1039/b203260kCéspedes-Guirao, F. J., B. Ropero, A., Font-Sanchis, E., Nadal, Á., Fernández-Lázaro, F., & Sastre-Santos, Á. (2011). A water-soluble perylene dye functionalised with a 17β-estradiol: a new fluorescent tool for steroid hormones. Chemical Communications, 47(29), 8307. doi:10.1039/c1cc10966aCéspedes-Guirao, F. J., Martín-Gomis, L., Ohkubo, K., Fukuzumi, S., Fernández-Lázaro, F., & Sastre-Santos, Á. (2011). Synthesis and Photophysics of Silicon Phthalocyanine-Perylenebisimide Triads Connected through Rigid and Flexible Bridges. Chemistry - A European Journal, 17(33), 9153-9163. doi:10.1002/chem.201100320Bodapati, J. B., & Icil, H. (2008). Highly soluble perylene diimide and oligomeric diimide dyes combining perylene and hexa(ethylene glycol) units: Synthesis, characterization, optical and electrochemical properties. Dyes and Pigments, 79(3), 224-235. doi:10.1016/j.dyepig.2008.02.009Zhang, F., Ma, Y., Chi, Y., Yu, H., Li, Y., Jiang, T., … Shi, J. (2018). Self-assembly, optical and electrical properties of perylene diimide dyes bearing unsymmetrical substituents at bay position. Scientific Reports, 8(1). doi:10.1038/s41598-018-26502-5Taguchi, A., & Schüth, F. (2005). Ordered mesoporous materials in catalysis. Microporous and Mesoporous Materials, 77(1), 1-45. doi:10.1016/j.micromeso.2004.06.030Trong On, D., Desplantier-Giscard, D., Danumah, C., & Kaliaguine, S. (2001). Perspectives in catalytic applications of mesostructured materials. Applied Catalysis A: General, 222(1-2), 299-357. doi:10.1016/s0926-860x(01)00842-0Carrillo, A. I., García-Martínez, J., Llusar, R., Serrano, E., Sorribes, I., Vicent, C., & Alejandro Vidal-Moya, J. (2012). Incorporation of cubane-type Mo3S4 molybdenum cluster sulfides in the framework of mesoporous silica. Microporous and Mesoporous Materials, 151, 380-389. doi:10.1016/j.micromeso.2011.10.005Garcia-Martinez, J., Linares, N., Sinibaldi, S., Coronado, E., & Ribera, A. (2009). Incorporation of Pd nanoparticles in mesostructured silica. Microporous and Mesoporous Materials, 117(1-2), 170-177. doi:10.1016/j.micromeso.2008.06.038Sriramulu, D., Turaga, S. P., Bettiol, A. A., & Valiyaveettil, S. (2017). Molecular Organization Induced Anisotropic Properties of Perylene – Silica Hybrid Nanoparticles. Scientific Reports, 7(1). doi:10.1038/s41598-017-07892-4Wahab, M. A., Hussain, H., & He, C. (2009). Photoactive Perylenediimide-Bridged Silsesquioxane Functionalized Periodic Mesoporous Organosilica Thin Films (PMO-SBA15): Synthesis, Self-Assembly, and Photoluminescent and Enhanced Mechanical Properties. Langmuir, 25(8), 4743-4750. doi:10.1021/la900042gRonzani, F., Saint-Cricq, P., Arzoumanian, E., Pigot, T., Blanc, S., Oelgemöller, M., … Lacombe, S. (2013). Immobilized Organic Photosensitizers with Versatile Reactivity for Various Visible-Light Applications. Photochemistry and Photobiology, 90(2), 358-368. doi:10.1111/php.12166Shang, J., Tang, H., Ji, H., Ma, W., Chen, C., & Zhao, J. (2017). Synthesis, characterization, and activity of a covalently anchored heterogeneous perylene diimide photocatalyst. Chinese Journal of Catalysis, 38(12), 2094-2101. doi:10.1016/s1872-2067(17)62960-7Lanterna, A. E., Elhage, A., & Scaiano, J. C. (2015). Heterogeneous photocatalytic C–C coupling: mechanism of plasmon-mediated reductive dimerization of benzyl bromides by supported gold nanoparticles. Catalysis Science & Technology, 5(9), 4336-4340. doi:10.1039/c5cy00655dMarquez, D. T., Carrillo, A. I., & Scaiano, J. C. (2013). Plasmon Excitation of Supported Gold Nanoparticles Can Control Molecular Release from Supramolecular Systems. Langmuir, 29(33), 10521-10528. doi:10.1021/la4019794Albiter, E., Alfaro, S., & Valenzuela, M. A. (2015). Photosensitized oxidation of 9,10-dimethylanthracene with singlet oxygen by using a safranin O/silica composite under visible light. Photochemical & Photobiological Sciences, 14(3), 597-602. doi:10.1039/c4pp00261jPrusakova, V., McCusker, C. E., & Castellano, F. N. (2012). Ligand-Localized Triplet-State Photophysics in a Platinum(II) Terpyridyl Perylenediimideacetylide. Inorganic Chemistry, 51(15), 8589-8598. doi:10.1021/ic301169tSimonutti, R., Comotti, A., Bracco, S., & Sozzani, P. (2001). Surfactant Organization in MCM-41 Mesoporous Materials As Studied by13C and29Si Solid-State NMR. Chemistry of Materials, 13(3), 771-777. doi:10.1021/cm001088iCardelli, A., Ricci, L., Ruggeri, G., Borsacchi, S., & Geppi, M. (2011). Optical properties of a polyethylene dispersion with a luminescent silica prepared by surface grafting of a perylene derivative. European Polymer Journal, 47(8), 1589-1600. doi:10.1016/j.eurpolymj.2011.05.006Prathapan, S., Yang, S. I., Seth, J., Miller, M. A., Bocian, D. F., Holten, D., & Lindsey, J. S. (2001). Synthesis and Excited-State Photodynamics of Perylene−Porphyrin Dyads. 1. Parallel Energy and Charge Transfer via a Diphenylethyne Linker. The Journal of Physical Chemistry B, 105(34), 8237-8248. doi:10.1021/jp010335iFord, W. E., & Kamat, P. V. (1987). Photochemistry of 3,4,9,10-perylenetetracarboxylic dianhydride dyes. 3. Singlet and triplet excited-state properties of the bis(2,5-di-tert-butylphenyl)imide derivative. The Journal of Physical Chemistry, 91(25), 6373-6380. doi:10.1021/j100309a012Ghirotti, M., Chiorboli, C., You, C.-C., Würthner, F., & Scandola, F. (2008). Photoinduced Energy and Electron-Transfer Processes in Porphyrin−Perylene Bisimide Symmetric Triads. The Journal of Physical Chemistry A, 112(15), 3376-3385. doi:10.1021/jp7109516Olea, A. F., & Wilkinson, F. (1995). Singlet Oxygen Production from Excited Singlet and Triplet States of Anthracene Derivatives in Acetonitrile. The Journal of Physical Chemistry, 99(13), 4518-4524. doi:10.1021/j100013a022Wilkinson, F., Helman, W. P., & Ross, A. B. (1993). Quantum Yields for the Photosensitized Formation of the Lowest Electronically Excited Singlet State of Molecular Oxygen in Solution. Journal of Physical and Chemical Reference Data, 22(1), 113-262. doi:10.1063/1.555934Zhao, Y. Z., Li, K. X., Ding, S. Y., Zhu, M., Ren, H. P., Ma, Q., … Miao, Z. C. (2018). The Effect of Reduction Potential on the Generation of the Perylene Diimide Radical Anions. Russian Journal of Physical Chemistry A, 92(7), 1261-1265. doi:10.1134/s003602441807035xDaw, P., Petakamsetty, R., Sarbajna, A., Laha, S., Ramapanicker, R., & Bera, J. K. (2014). A Highly Efficient Catalyst for Selective Oxidative Scission of Olefins to Aldehydes: Abnormal-NHC–Ru(II) Complex in Oxidation Chemistry. Journal of the American Chemical Society, 136(40), 13987-13990. doi:10.1021/ja5075294Nyawade, E. A., Friedrich, H. B., Omondi, B., & Mpungose, P. (2015). Synthesis and Characterization of New (η5-Cyclopentadienyl)dicarbonylruthenium(II) Amine Complexes: Their Application as Homogeneous Catalysts in Styrene Oxidation. Organometallics, 34(20), 4922-4931. doi:10.1021/acs.organomet.5b00564Muthumari, S., & Ramesh, R. (2018). Synthesis and Structure of Ru(II) Complexes of Thiosemicarbazone: Highly Selective Catalysts for Oxidative Scission of Olefins to Aldehydes. ChemistrySelect, 3(11), 3036-3041. doi:10.1002/slct.20180016

Glass wool: a novel support for heterogeneous catalysis

[EN] Heterogeneous catalysis presents significant advantages over homogeneous catalysis such as ease of separation and reuse of the catalyst. Here we show that a very inexpensive, manageable and widely available material - glass wool - can act as a catalyst support for a number of different reactions. Different metal and metal oxide nanoparticles, based on Pd, Co, Cu, Au and Ru, were deposited on glass wool and used as heterogeneous catalysts for a variety of thermal and photochemical organic reactions including reductive de-halogenation of aryl halides, reduction of nitrobenzene, Csp(3)-Csp(3) couplings, N-C heterocycloadditions (click chemistry) and Csp-Csp(2) couplings (Sonogashira couplings). The use of glass wool as a catalyst support for important organic reactions, particularly C-C couplings, opens the opportunity to develop economical heterogeneous catalysts with excellent potential for flow photo-chemistry application.This work was supported by the Natural Sciences and Engineering Research Council of Canada, the Canada Foundation for Innovation, the Canada Research Chairs Program and funding from Canada's International Development Research Centre (IDRC). Thanks are due to the RISE program for the scholarship awarded to M. C. and the Generalitat Valenciana (BEST/2017/049) for the financial support granted to M. L. M. The authors would like to thank Dr Yun Liu for helping on the acquisition of the SEM images.Elhage, A.; Wang, B.; Marina, N.; Marín García, ML.; Cruz, M.; Lanterna, AE.; Scaiano, JC. (2018). Glass wool: a novel support for heterogeneous catalysis. Chemical Science. 9(33):6844-6852. https://doi.org/10.1039/c8sc02115eS68446852933Davies, I. W., Matty, L., Hughes, D. L., & Reider, P. J. (2001). Are Heterogeneous Catalysts Precursors to Homogeneous Catalysts? Journal of the American Chemical Society, 123(41), 10139-10140. doi:10.1021/ja016877vConner, W. C., & Falconer, J. L. (1995). Spillover in Heterogeneous Catalysis. Chemical Reviews, 95(3), 759-788. doi:10.1021/cr00035a014Elhage, A., Lanterna, A. E., & Scaiano, J. C. (2016). Tunable Photocatalytic Activity of Palladium-Decorated TiO2: Non-Hydrogen-Mediated Hydrogenation or Isomerization of Benzyl-Substituted Alkenes. ACS Catalysis, 7(1), 250-255. doi:10.1021/acscatal.6b02832Cambié, D., Bottecchia, C., Straathof, N. J. W., Hessel, V., & Noël, T. (2016). Applications of Continuous-Flow Photochemistry in Organic Synthesis, Material Science, and Water Treatment. Chemical Reviews, 116(17), 10276-10341. doi:10.1021/acs.chemrev.5b00707Lanterna, A. E., Elhage, A., & Scaiano, J. C. (2015). Heterogeneous photocatalytic C–C coupling: mechanism of plasmon-mediated reductive dimerization of benzyl bromides by supported gold nanoparticles. Catalysis Science & Technology, 5(9), 4336-4340. doi:10.1039/c5cy00655dWang, B., Durantini, J., Nie, J., Lanterna, A. E., & Scaiano, J. C. (2016). Heterogeneous Photocatalytic Click Chemistry. Journal of the American Chemical Society, 138(40), 13127-13130. doi:10.1021/jacs.6b06922Sigma-Aldrich, Glass Wool, http://www.sigmaaldrich.com/catalog/product/supelco/20411?lang=en&region=CA , accessed September, 2017, 2017Steyn, B., Oosthuizen, M. C., MacDonald, R., Theron, J., & Brözel, V. S. (2001). The use of glass wool as an attachment surface for studying phenotypic changes inPseudomonas aeruginosa biofilms by two-dimensional gel electrophoresis. PROTEOMICS, 1(7), 871-879. doi:10.1002/1615-9861(200107)1:73.0.co;2-2Nisnevitch, M., Kolog-Gulco, M., Trombka, D., Green, B. ., & Firer, M. . (2000). Immobilization of antibodies onto glass wool. Journal of Chromatography B: Biomedical Sciences and Applications, 738(2), 217-223. doi:10.1016/s0378-4347(99)00514-9Matatov-Meytal, Y., & Sheintuch, M. (2002). Catalytic fibers and cloths. Applied Catalysis A: General, 231(1-2), 1-16. doi:10.1016/s0926-860x(01)00963-2Barelko, V. V., Kuznetsov, M. V., Dorokhov, V. G., & Parkin, I. (2017). Glass-fiber woven catalysts as alternative catalytic materials for various industries. A review. Russian Journal of Physical Chemistry B, 11(4), 606-617. doi:10.1134/s1990793117040030Macdonald, R. W., & Hayes, K. E. (1972). Glass wool as an oxidation catalyst. Journal of the Chemical Society, Chemical Communications, (18), 1030a. doi:10.1039/c3972001030aRamaswamy, G. K., Somasundaram, A., Kuppuswamy, B. K., & Velayudham, M. (2012). Glass Wool Catalysed Regioselective Isomerization of Styrene Oxides. Journal of the Chinese Chemical Society, 60(1), 97-102. doi:10.1002/jccs.201200269YANG, H., FANG, Z., FU, X., & TONG, L. (2007). A Novel Glass Fiber-Supported Platinum Catalyst for Self-healing Polymer Composites: Structure and Reactivity. Chinese Journal of Catalysis, 28(11), 947-952. doi:10.1016/s1872-2067(07)60081-3Bal’zhinimaev, B. S., Suknev, A. P., Gulyaeva, Y. K., & Kovalyov, E. V. (2015). Silicate fiberglass catalysts: From science to technology. Catalysis in Industry, 7(4), 267-274. doi:10.1134/s2070050415040029Simonova, L. G., Barelko, V. V., Toktarev, A. V., Chernyshov, A. F., Chumachenko, V. A., & Bal’zhinimaev, B. S. (2002). Kinetics and Catalysis, 43(1), 61-66. doi:10.1023/a:1014249129178Carrillo, A. I., Stamplecoskie, K. G., Marin, M. L., & Scaiano, J. C. (2014). ‘From the mole to the molecule’: ruthenium catalyzed nitroarene reduction studied with ‘bench’, high-throughput and single molecule fluorescence techniques. Catal. Sci. Technol., 4(7), 1989-1996. doi:10.1039/c4cy00018hMorgan, D. J. (2015). Resolving ruthenium: XPS studies of common ruthenium materials. Surface and Interface Analysis, 47(11), 1072-1079. doi:10.1002/sia.5852Park, K. C., Jang, I. Y., Wongwiriyapan, W., Morimoto, S., Kim, Y. J., Jung, Y. C., … Endo, M. (2010). Carbon-supported Pt–Ru nanoparticles prepared in glyoxylate-reduction system promoting precursor–support interaction. Journal of Materials Chemistry, 20(25), 5345. doi:10.1039/b923153fBock, C., Paquet, C., Couillard, M., Botton, G. A., & MacDougall, B. R. (2004). Size-Selected Synthesis of PtRu Nano-Catalysts:  Reaction and Size Control Mechanism. Journal of the American Chemical Society, 126(25), 8028-8037. doi:10.1021/ja0495819Espinós, J. P., Morales, J., Barranco, A., Caballero, A., Holgado, J. P., & González-Elipe, A. R. (2002). Interface Effects for Cu, CuO, and Cu2O Deposited on SiO2and ZrO2. XPS Determination of the Valence State of Copper in Cu/SiO2and Cu/ZrO2Catalysts. The Journal of Physical Chemistry B, 106(27), 6921-6929. doi:10.1021/jp014618mKlyushin, A. Y., Rocha, T. C. R., Hävecker, M., Knop-Gericke, A., & Schlögl, R. (2014). A near ambient pressure XPS study of Au oxidation. Physical Chemistry Chemical Physics, 16(17), 7881. doi:10.1039/c4cp00308jHigman, C. S., Lanterna, A. E., Marin, M. L., Scaiano, J. C., & Fogg, D. E. (2016). Catalyst Decomposition during Olefin Metathesis Yields Isomerization-Active Ruthenium Nanoparticles. ChemCatChem, 8(15), 2446-2449. doi:10.1002/cctc.201600738Bedford, R. B., Cazin, C. S. J., & Holder, D. (2004). The development of palladium catalysts for CC and Cheteroatom bond forming reactions of aryl chloride substrates. Coordination Chemistry Reviews, 248(21-24), 2283-2321. doi:10.1016/j.ccr.2004.06.012CRC Handbook of Chemistry and Physics , ed. D. R. Lide , Taylor and Francis Group , Boca Raton, FL , 88th edn, 2007 , p. 2640Sahoo, B., Surkus, A.-E., Pohl, M.-M., Radnik, J., Schneider, M., Bachmann, S., … Beller, M. (2017). A Biomass-Derived Non-Noble Cobalt Catalyst for Selective Hydrodehalogenation of Alkyl and (Hetero)Aryl Halides. Angewandte Chemie, 129(37), 11394-11399. doi:10.1002/ange.201702478Devery, J. J., Nguyen, J. D., Dai, C., & Stephenson, C. R. J. (2016). Light-Mediated Reductive Debromination of Unactivated Alkyl and Aryl Bromides. ACS Catalysis, 6(9), 5962-5967. doi:10.1021/acscatal.6b01914Liao, L., Zhang, Q., Su, Z., Zhao, Z., Wang, Y., Li, Y., … Bao, J. (2013). Efficient solar water-splitting using a nanocrystalline CoO photocatalyst. Nature Nanotechnology, 9(1), 69-73. doi:10.1038/nnano.2013.272Hainer, A. S., Hodgins, J. S., Sandre, V., Vallieres, M., Lanterna, A. E., & Scaiano, J. C. (2018). Photocatalytic Hydrogen Generation Using Metal-Decorated TiO2: Sacrificial Donors vs True Water Splitting. ACS Energy Letters, 3(3), 542-545. doi:10.1021/acsenergylett.8b00152Elhage, A., Lanterna, A. E., & Scaiano, J. C. (2018). Light-Induced Sonogashira C–C Coupling under Mild Conditions Using Supported Palladium Nanoparticles. ACS Sustainable Chemistry & Engineering, 6(2), 1717-1722. doi:10.1021/acssuschemeng.7b02992Roy, P., Periasamy, A. P., Liang, C.-T., & Chang, H.-T. (2013). Synthesis of Graphene-ZnO-Au Nanocomposites for Efficient Photocatalytic Reduction of Nitrobenzene. Environmental Science & Technology, 47(12), 6688-6695. doi:10.1021/es400422kZhou, B., Song, J., Zhou, H., Wu, L., Wu, T., Liu, Z., & Han, B. (2015). Light-driven integration of the reduction of nitrobenzene to aniline and the transformation of glycerol into valuable chemicals in water. RSC Advances, 5(46), 36347-36352. doi:10.1039/c5ra06354jZhu, H., Ke, X., Yang, X., Sarina, S., & Liu, H. (2010). Reduction of Nitroaromatic Compounds on Supported Gold Nanoparticles by Visible and Ultraviolet Light. Angewandte Chemie International Edition, 49(50), 9657-9661. doi:10.1002/anie.201003908Selvam, K., Sakamoto, H., Shiraishi, Y., & Hirai, T. (2015). Photocatalytic secondary amine synthesis from azobenzenes and alcohols on TiO2 loaded with Pd nanoparticles. New Journal of Chemistry, 39(4), 2856-2860. doi:10.1039/c5nj00158gSarina, S., Waclawik, E. R., & Zhu, H. (2013). Photocatalysis on supported gold and silver nanoparticles under ultraviolet and visible light irradiation. Green Chemistry, 15(7), 1814. doi:10.1039/c3gc40450aWang, L., Pan, X., Zhao, Y., Chen, Y., Zhang, W., Tu, Y., … Zhu, X. (2015). A Straightforward Protocol for the Highly Efficient Preparation of Main-Chain Azo Polymers Directly from Bisnitroaromatic Compounds by the Photocatalytic Process. Macromolecules, 48(5), 1289-1295. doi:10.1021/acs.macromol.5b00048Bandara, H. M. D., & Burdette, S. C. (2012). Photoisomerization in different classes of azobenzene. Chem. Soc. Rev., 41(5), 1809-1825. doi:10.1039/c1cs15179gMcGilvray, K. L., Decan, M. R., Wang, D., & Scaiano, J. C. (2006). Facile Photochemical Synthesis of Unprotected Aqueous Gold Nanoparticles. Journal of the American Chemical Society, 128(50), 15980-15981. doi:10.1021/ja066522

Tunable Photocatalytic Activity of Palladium-Decorated TiO2: Non-Hydrogen-Mediated Hydrogenation or Isomerization of Benzyl-Substituted Alkenes

Palladium-decorated TiO2 is a moisture- and air-tolerant versatile catalyst. Its photocatalytic activity can be tuned in favor of hydrogenation or isomerization of benzyl-substituted alkenes simply by changing the irradiation wavelength. Benzyl-substituted alkenes are selectively isomerized to phenyl-substituted alkenes (E-isomer) with complete conversion over Pd@TiO2 under H2-free conditions. The reaction can be thermally induced under air or driven by visible-light irradiation at room temperature under Ar. UV irradiation in methanol solvent leads to efficient hydrogenation. The fine-tunability of the catalyst can also be used for selective deuterium incorporation using deuterated solvents; here H/D exchange is used as a mechanistic tool but with clear potential for isotope substitution applications

Heterogeneous photocatalytic C–C coupling: mechanism of plasmon-mediated reductive dimerization of benzyl bromides by supported gold nanoparticles

The use of gold nanoparticles supported on TiO2 (Au@TiO2) as photocatalysts was extended to include photoinduced reductive C–C coupling. Surface plasmon excitation of supported AuNPs in the presence of an amine leads to the C–C coupling of a variety of substituted benzyl bromides at room temperature with good yields in a free radical-mediated reaction. The overall efficiency of the C–C coupling is largely dependent on the nature of the amine used

Light-Induced Sonogashira C–C Coupling under Mild Conditions Using Supported Palladium Nanoparticles

The Sonogashira reaction can easily be photocatalyzed by supported palladium nanoparticles. Herein, we demonstrate that the direct excitation of PdNPs can catalyze the C–C coupling between different aryl iodides and acetylenes under very mild conditions in short reaction times. The catalyst is air- and moisture-tolerant and can be supported on a wide range of materials, including inert ones such as nanodiamonds. Study of the action spectrum demonstrates that direct excitation of the PdNPs is required, and in the case of Pd@TiO₂, for example, visible excitation works well whereas UVA (368 nm) irradiation is ineffective because of TiO₂ shielding the Pd absorption. The catalyst can be reused a couple of times, but when it loses activity, it can be readily reactivated by a simple reductive photochemical strategy

Tunable Photocatalytic Activity of Palladium-Decorated TiO₂: Non-Hydrogen-Mediated Hydrogenation or Isomerization of Benzyl-Substituted Alkenes

Palladium-decorated TiO₂ is a moisture- and air-tolerant versatile catalyst. Its photocatalytic activity can be tuned in favor of hydrogenation or isomerization of benzyl-substituted alkenes simply by changing the irradiation wavelength. Benzyl-substituted alkenes are selectively isomerized to phenyl-substituted alkenes (<i>E</i>-isomer) with complete conversion over Pd@TiO₂ under H₂-free conditions. The reaction can be thermally induced under air or driven by visible-light irradiation at room temperature under Ar. UV irradiation in methanol solvent leads to efficient hydrogenation. The fine-tunability of the catalyst can also be used for selective deuterium incorporation using deuterated solvents; here H/D exchange is used as a mechanistic tool but with clear potential for isotope substitution applications