Resistance to sulfur poisoning of Rh supported catalysts

Abstract

Sulfur thiotolerance by thiophene during toluene hydrogenation on rhodium supported catalysts prepared on different supports and metal precursors have been studied. The catalysts were characterized by H2 chemisorption, TEM;~TPD of ammonia and XPS. ~The turnover frequency of the reaction does not change sit, nificantly with the carrier but in the presence of 10 ppm ofthiophene a drastic decrease in the activity is observed. The initial deactivation constant follows the order Rh/SiO2 > Rh/TiO2 > Rh/A]2O3.

Synthesis and Characterization of Dendrimer-Derived Supported Iridium Catalysts

“…Supported iridium catalysts are outstanding candidates for a variety of catalytic reactions due to their stability, activity and selectivity under reaction conditions. − For example, Ir catalysts possess unique characteristics for effective and selective synthesis of substituted N -aryl-hydroxylamines, chloro-substituted anilines and both symmetric and asymmetric azoxybenzenes . Furthermore, supported Ir has been successfully employed for hydrogenation of α,β-unsaturated aldehydes to selectively produce unsaturated alcohols. ,,− Supported Ir catalysts are commonly prepared via wet impregnation ,,− and incipient wetness impregnation. ,− …”

“…6 Furthermore, supported Ir has been successfully employed for hydrogenation of R,β-unsaturated aldehydes to selectively produce unsaturated alcohols. 4,5,[7][8][9][10][11] Supported Ir catalysts are commonly prepared via wet impregnation 4,5,[12][13][14][15][16] and incipient wetness impregnation. 11, [17][18][19][20] In supported metal catalysts, it is often desired to minimize the amount of noble metal needed (i.e., cost) by maximizing the metal surface area per unit volume.…”