Synthetic control of defect structure and hierarchical extra-large/small-pore microporosity in aluminosilicate zeolite SWY

R.G.C. thanks the University of St. Andrews and Johnson Matthey for funding. P.A.W. thanks the Royal Society (Industrial Fellowship INF\R2\192052) for support. R.G.C. acknowledges the support of the EPSRC Light Element Analysis Facility grant EP/T019298/1 and the EPSRC Strategic Equipment Resource grant EP/R023751/1 for the use of the Jeol JSM-IT800 electron microscope at the University of St Andrews. A.M. acknowledges the Spanish Ministry of Science (RYC2018-024561-I) and the Gobierno of Aragon (Nanomidas group, code E13_23R).The SWY-type aluminosilicate zeolite, STA-30, has been synthesized via different routes to understand its defect chemistry and solid acidity. The synthetic parameters varied were the gel aging, the Al source, and the organic structure directing agent. All syntheses give crystalline materials with similar Si/Al ratios (6–7) that are stable in the activated K,H-form and closely similar by powder X-ray diffraction. However, they exhibit major differences in the crystal morphology and in their intracrystalline porosity and silanol concentrations. The diDABCO-C82+ (1,1′-(octane-1,8-diyl)bis(1,4-diazabicyclo[2.2.2]octan)-1-ium)-templated STA-30 samples (but not those templated by bisquinuclidinium octane, diQuin-C82+) possess hierarchical microporosity, consisting of noncrystallographic extra-large micropores (13 Å) that connect with the characteristic swy and gme cages of the SWY structure. This results in pore volumes up to 30% greater than those measured in activated diQuin-C8_STA-30 as well as higher concentrations of silanols and fewer Brønsted acid sites (BASs). The hierarchical porosity is demonstrated by isopentane adsorption and the FTIR of adsorbed pyridine, which shows that up to 77% of the BASs are accessible (remarkable for a zeolite that has a small-pore crystal structure). A structural model of single can/d6r column vacancies is proposed for the extra-large micropores, which is revealed unambiguously by high-resolution scanning transmission electron microscopy. STA-30 can therefore be prepared as a hierarchically porous zeolite via direct synthesis. The additional noncrystallographic porosity and, subsequently, the amount of SiOHs in the zeolites can be enhanced or strongly reduced by the choice of crystallization conditions.Publisher PDFPeer reviewe

Site-Specific Iron Substitution in STA-28, a Large Pore Aluminophosphate Zeotype Prepared by Using 1, 10-Phenanthrolines as Framework-Bound Templates

An AlPO4 zeotype has been prepared using the aromatic diamine 1, 10-phenanthroline and some of its methylated analogues as templates. In each case the two template N atoms bind to a specific framework Al site to expand its coordination to the unusual octahedral AlO4N2 environment. Furthermore, using this framework-bound template, Fe atoms can be included selectively at this site in the framework by direct synthesis, as confirmed by annular dark field scanning transmission electron microscopy and Rietveld refinement. Calcination removes the organic molecules to give large pore framework solids, with BET surface areas up to 540 m2 g-1 and two perpendicular sets of channels that intersect to give pore space connected by 12-ring openings along all crystallographic directions

Understanding the structure directing action of copper-polyamine complexes in the direct synthesis of Cu-SAPO-34 and Cu-SAPO-18 catalysts for the selective catalytic reduction of NO with NH3

This work has been supported by Johnson Matthey PLC, UK.Cu2+ cations complexed by linear polyamines have been studied as structure-directing agents (SDAs) for the direct synthesis of copper-containing microporous silicoaluminophosphate (SAPO) materials. The complexing ligands diethylenetriamine (DETA), N-(2-hydroxyethyl)ethylenediamine (HEEDA), triethylenetetramine (TETA), N,N′-bis(2-aminoethyl)-1,3-propanediamine (232), 1,2-bis(3-aminopropylamino)ethane (323), tetraethylenepentamine (TEPA) and pentaethylenehexamine (PEHA) have been investigated. For comparison, syntheses have been performed using the analogous nickel-polyamine complexes. Cu2+ and Ni2+ forms of both SAPO-18 and SAPO-34 materials have been prepared. While most polyamine complexes direct crystallisation to SAPO-34, SAPO-18 has been prepared with Cu2+(232), Ni2+(232) and Ni2+(TETA). The coordination geometry of the included metal complexes was studied by UV-visible and EPR spectroscopy and computer simulation. SAPO-18 is favoured by the smaller square planar complexes or octahedral species (with 2 water molecules) of 232 and TETA. Calcination leaves extra-framework Cu2+ and Ni2+ cations within SAPO-18 and SAPO-34 frameworks. In situ synchrotron IR spectroscopy of Ni-SAPO-18 has shown thermal template degradation occurs via nitrile intermediates. Rietveld structural analysis located extra-framework Cu2+ and Ni2+ cations released by calcination. In SAPO-34, Cu2+ and Ni2+ were located in the 8R window of the cha cage. A second site was found for Ni2+ at the centre of the six-membered rings (6Rs) of the double-six-ring (D6R) sub-units. In SAPO-18 both Cu2+ and Ni2+ cations were located only in the 6Rs of the D6R sub-units. Selected copper SAPO-18 and SAPO-34 samples were tested in the selective catalytic reduction of NO with ammonia (NH3-SCR); both showed high activity.PostprintPostprintPeer reviewe

THE HBIM ANALYSIS OF THE GEOMETRY TO UNDERSTAND THE CONSTRUCTIVE TECHNIQUE: THE USE OF THE <i>TROMPE</i> VOLUME IN A BRICK VAULT

The construction of brick-vaulted systems between the 16th and 18th centuries is a typical mark among the noble buildings in large part of Northern Italy. Nowadays they are still a witness of a high level of constructive knowledge by workers, formalized in historical treatises and manuals supporting a literature of theories and practices known since ancient times. The way a vault is geometrically built, regardless of its typology, is not unique and it differs in treatises, according to its location in time and space. The consequence is the generation of “mixed” solutions, where the result of the final volume is achieved by the integration of different generative models and spatial solutions. The observation of cloister vaults, apparently similar to each other but built adopting different constructive techniques within a single building, Magio Grasselli Palace in Cremona, helped to understand this topic

A retrosynthetic co-templating method for the preparation of silicoaluminophosphate molecular sieves

This work has been supported by Johnson Matthey PLC, UK. Solid-state NMR spectra were obtained at the EPSRC UK National Solid-state NMR Service at Durham.A retrosynthetic method has been developed to design the synthesis of target zeotypes whose frameworks belong to the ABC-6 structural family and which contain gme cages. This permits the preparation of silicoaluminophosphate versions of AFX (SAPO-56), SFW (STA- 18) and GME (STA-19) topology types. The method makes simultaneous use of two organic structure directing agents (SDAs) to promote the formation of structural features such as cages or channels of the target framework. Computational modelling was used to identify SDAs for gme and other cages or channels in the target structures. The trimethylammonium cation was found to be the most favourable SDA for the gme cage while bisdiazabicyclooctane (DABCO) alkane cations and quaternary ammonium oligomers of DABCO with connecting polymethylene chain lengths of 4 to 8 methylene units acted as 1 templates for the additional cages or channels, respectively. The incorporation of each of the co-SDAs in the as-prepared materials was confirmed by chemical analysis, 13C MAS NMR and Rietveld refinement combined with computational modeling. Calcination of the SAPO- 56, STA-18 and some of the STA-19 materials gives microporous, fully tetrahedrally- coordinated framework solids with AFX, SFW and GME topologies: other STA-19 samples convert topotactically to SAPO-5. These results show that SAPOs in the ABC-6 family can be prepared via a targeted co-templating approach.PostprintPostprintPeer reviewe

Synthesis and activation for catalysis of Fe-SAPO-34 prepared using iron polyamine complexes as structure directing agents

This work was supported by Johnson Matthey PLC, UK. Solid-state NMR spectra were obtained at the EPSRC UK National Solid-state NMR Service at Durham.The use of transition metal cations complexed by polyamines as structure directing agents (SDAs) for silicoaluminophosphate (SAPO) zeotypes provides a route, via removal of the organic by calcination, to microporous solids with well-distributed, catalytically-active extra-framework cations and avoids the need for post-synthesis aqueous cation exchange. Iron(II) complexed with tetraethylenepentamine (TEPA) is found to be an effective SDA for SAPO- 34, giving as-prepared solids where Fe2+-TEPA complexes reside within the cha cages, as indicated by Mössbauer, optical and X-ray absorption near edge spectroscopies. By contrast, when non-coordinating tetraethylammonium ions are used as the SDAs in Fe-SAPO-34 preparations, iron is included as octahedral Fe3+ within the framework. The complex- containing Fe-SAPO-34(TEPA) materials give a characteristic visible absorption band at 550 nm (and purple colouration) when dried in air that is attributed to oxygen chemisorption. Some other Fe2+ polyamine complexes (diethylenetriamine, triethylenetetramine and pentaethylenehexamine) show similar behaviour. After calcination in flowing oxygen at 550 °C, ‘one-pot’ Fe(TEPA) materials possess Fe3+ cations and a characteristic UV-visible spectrum: they also show appreciable activity in the selective catalytic reduction of NO with NH3.PostprintPostprintPeer reviewe

Religion as a Cross-cultural Determinant of Depression in Elderly Europeans: Results from the EURODEP Collaboration

Background. The protective effects of religion against late life depression may depend on the broader sociocultural environment. This paper examines whether the prevailing religious climate is related to cross-cultural differences of depression in elderly Europeans. Methods. Two approaches were employed, using data from the EURODEP collaboration. First, associations were studied between church-attendance, religious denomination and depression at the syndrome level for six EURODEP study centres (five countries, N = 8398). Secondly, ecological associations were computed by multi-level analysis between national estimates of religious climate, derived from the European Value Survey and depressive symptoms, for the pooled dataset of 13 EURODEP study centres (11 countries, N = 17739). Results. In the first study, depression rates were lower among regular church-attenders, most prominently among Roman Catholics. In the second study, fewer depressive symptoms were found among the female elderly in countries, generally Roman Catholic, with high rates of regular church-attendance. Higher levels of depressive symptoms were found among the male elderly in Protestant countries. Conclusions. Religious practice is associated with less depression in elderly Europeans, both on the individual and the national level. Religious practice, especially when it is embedded within a traditional value-orientation, may facilitate coping with adversity in later life

Functional disability and death wishes in older Europeans: results from the EURODEP concerted action

Functional disability was independently associated with death wishes in older adults. Results can help inform clinicians who care for older persons with functional impairment.</p

STA-20 : an ABC-6 zeotype structure prepared by co-templating and solved via a hypothetical structure database and STEM-ADF imaging

This work has been supported by Johnson Matthey PLC, UK. AEW acknowledges funding from an EPSRC/Johnson Matthey Industrial CASE PhD award EP/N50936X/1. We acknowledge Diamond Light Source for time on beamline I11 under the funded Proposal EE11830-1.A microporous silicoaluminophosphate with a novel topology type, STA-20, has been prepared via a dual templating method using hexamethylene bisdiazabicyclooctane (diDABCO-C6) and trimethylamine as co-templates. Its structure has been solved and confirmed using a multi-technique approach that included the use of a hypothetical zeolite database to obtain a candidate starting structure, followed by scanning transmission electron microscopy with annular dark field imaging and Rietveld refinement. STA-20 is a member of the ABC-6 family of zeotype structures. The structure has trigonal symmetry, P-31c, with a = 13.15497(18) Å and c = 30.5833(4) Å in the calcined form. It has a 12-layer stacking sequence of 6-rings (6Rs), AABAABAACAAC(A), which contains single and double 6R units. As well as d6r, can and gme cages, STA-20 possesses the longest cage observed in an ordered ABC-6 material, giving a 3D-connected pore system limited by 8R windows. Models for the location of the templates within cages of the framework were obtained by combining elemental analysis, 13C MAS NMR, computer modelling and Rietveld refinement.PostprintPostprintPeer reviewe