Improvement of propylene yield via butene metathesis

Includes synopsis.Includes bibliographical references (leaves [96]-100).There is an increasing interest in finding ways to produce on-purpose propene, due to the significant predicted propene growth in the next few years without the concomitant growth in the ethene demand, One of the technologies available is 1-butene metathesis, which describes a one-step process where isomerisation of 1-butene to 2-butene followed by cross-metathesis taking place. Products of the cross metathesis are propene and 2-pentene. In addition ethene and 3-hexene are expected as products of 1-butene metathesis

Catalytic abatement of trichloroethylene over Mo and/or W-based bronzes

[EN] In this paper we present the results of the synthesis, characterization and catalytic behaviour of Mo(W)¿Nb¿V¿O mixed metal oxides bronzes for the catalytic oxidation of trichloroethylene. The catalysts were prepared hydrothermally with different Mo/W/Nb/V/P atomic ratio and heat-treated at 500 and 700 °C. They were characterized by several techniques as N2-adsorption, X-ray diffraction, FTIR, SEM-EDS, temperature programmed desorption, temperature programmed reduction, UV¿vis, Fourier transformed infrared spectroscopy of adsorbed pyridine and 18O/16O isotope exchange. X-ray diffraction patterns (XRD) of samples heat-treated at 500 °C suggest the presence of a semi-crystalline material with a diffraction peak at ca. 2¿ = 22.2°, while XRD patterns of samples heat-treated at 700 °C show the formation of a tetragonal tungsten bronze (TTB) structure. The activity for the catalytic abatement of trichloroethylene strongly depends on the heat-treatment temperature and the catalyst composition. Thus, samples with W/(Mo + W) atomic ratios of 0.25-0.75 and heat-treated at 500 °C are the most active ones. The enhanced activity has been related to the remarkable higher surface area of the catalyst and to the catalyst composition which influences the acid characteristics as well as the reducibility and reoxidation of the catalysts. The importance of the oxygen dissociation on the catalyst surface and the diffusion of oxygen species through the catalyst are also discussed.The authors wish to thank DGICYT in Spain (Project CTQ2009-14495 and CSD2009-00050-CONSOLIDER/INGENIO 2010) and Universitat Politecnica de Valencia for the financial support. N.B.R. acknowledges Catedra Cemex Sostenibilidad (UPV) for a fellowship. M.D.S. acknowledges Universitat Politecnica de Valencia for a fellowship.Blanch Raga, N.; Soriano Rodríguez, MD.; Palomares Gimeno, AE.; Concepción Heydorn, P.; Martínez Triguero, LJ.; López Nieto, JM. (2013). Catalytic abatement of trichloroethylene over Mo and/or W-based bronzes. Applied Catalysis B: Environmental. 130-131:36-43. https://doi.org/10.1016/j.apcatb.2012.10.016S3643130-13