A highly active and selective silver on nickel fiber catalyst was successfully prepared for selective oxidation of benzyl alcohol. The Ag/Ni catalyst was obtained by loading Ag (10 wt%) on paper-like microfibrous structure (consisting of 5 vol% of 8- m Ni-fiber) by impregnation method. The wettability of Ni-fiber support was vastly improved by a simple water pre-wetting and overnight drying treatment process. This yielded a catalyst (Ag/Ni-fiber-M) with more Ag cations and selectively active oxygen species than the catalyst (Ag/Ni-fiber) using the untreated support. The Ag/Ni-fiber-M showed much higher lowtemperature activity/selectivity than the Ag/Ni-fiber, which could be attributed to the differences in their silver morphology and particle size. The best conversion and benzaldehyde selectivity observed were both 97% for Ag/Ni-fiber-M at 300 ◦C, and 91 and 84% for Ag/Ni-fiber at 380 ◦C, respectively. Benzyl alcohol selective oxidation would proceed concurrently through both directO2 activation route and NiOxparticipating oxygen spillover route. Formation of NixC phase occurred and hampered the latter reaction route thereby leading to partial deactivation. However, spent catalyst could restore activity through an oxidation treatment at 400 ◦C.

An aerobic oxidative removal of mercaptans from gasoline in the absence of liquid base has been demonstrated for gasoline sweetening over CuZnAl catalyst. This process could proceed at large WHSV of gasoline (50–70 h 1) with [95% mercaptan conversion at 150 C (or 300 C) using an O2/S molar ratio of 20–40. At 150 C, dimerization of mercaptans occurred dominantly to form their disulfides. At 300 C, deep oxidation of the mercaptans to SO2 was the dominant process in the first tens of hours, but it decreased then with prolonged time on stream and meanwhile the dimerization increased. The spent catalyst could be restored to its fresh activity level only through a calcination treatment in air. This process was also demonstrated to be ffective and efficient for sweetening of a real cracking gasoline.

A non-woven microfibrous thin-sheet structure with 5 vol% 8 lm diameter nickel fibers was built up using wet-lay papermaking and sintering process. Silver was then placed onto the sinter-locked Ni-fiber by the incipient wetness impregnation with AgNO3 aqueous solution. As-made Ag/Ni-fiber catalysts exhibited much higher activity/selectivity for the gas-phase selective oxidation of benzyl alcohol to benzaldehyde, and provided significant increase in the steady-state volumetric reaction rate with dramatic saving of Ag, in comparison with the electrolytic silver and Ag/a-Al2O3 catalysts. Conversion of 84% as achievable with benzaldehyde selectivity of 94% at 380 C using a high WHSV of 30 h 1.

A series of CuZnAl oxide-composite catalysts were prepared via ecomposition of CuZnAl hydrotalcite-like compounds (HTLcs). The catalysts derived from CuZnAl HTLcs (Cu: 37%, Zn: 15%, Al: 48% mol; using metal nitrate or acetate precursors) at 600 C provided excellent activity and stability for the methanol steam reforming. CuZnAl HTLcs were almost decomposed completely at 600 C to form highly dispersed CuO with large specific surface area while forming CuAl2O4 spinel that played a key role in separating and stabilizing the nano-sized Cu and ZnO during the reaction. The CuZnAl catalyst prepared from metal acetates could highly convert H2O/MeOH (1.3/1, mol/mol) mixture into hydrogen with only 0.05% CO at 250 C or 0.005% at 210 C. It is videnced that the former afforded stronger Cu-ZnO interaction, which might be the intrinsic reason for the significant promotion of catalyst electivity. VVC 2009 American Institute of Chemical Engineers AIChE J, 55: 1217-1228, 2009

Pt/CeO2–Al2O3 catalysts with and without Gd2O3 additive were prepared by stepwise incipient wetness impregnation (IWI) method. The catalysts were tested for autothermal reforming (ATR) of retail gasoline containing 158–500 ppm sulfur under the optimal reaction conditions: 800 8C, gasoline WHSV of 0.9 h 1 and aH2O/O2/Cmolar ratio of 5/0.35/1. It is foundthat the content ofGd2O3 and impregnationprocedure for catalyst preparation significantly affected the catalyst performance. Pt catalyst supported on the Al2O3 that was pre-impregnated with Ce and Gd nitrates orderly to 15 wt% CeO2 and 1.6 wt% Gd2O3 was the best catalyst forATRof gasoline with high reactivity and excellent stability. Within 1000-h ATRof retail asoline over this catalyst, gasoline conversion was slowly decreased to 95% after 300-h run and then remained at 95% throughout the test, while H2 fraction in reformate remained at 67% with a CH4 fraction less than 0.6%. It is revealed that modification of Al2O3 with CeO2 first and Gd2O3 then endowed the produced Pt catalyst withmany advantageous effects such as significantly improved and stabilized Pt-CeO2 interaction, greatly attenuated Pt-sintering, and enhanced oxygen ion conductivity of bulk CeO2.