Enhanced selectivity in acetylenehydrogenation by ligand modified Pd/TiO₂catalysts

Abstract

Modification of Pd/TiO(2) catalyst by adsorption of triphenylphosphine and phenyl sulfide leads to markedly enhanced selectivity for acetylene hydrogenation in the presence of ethylene and excess hydrogen. Similar selectivities were maintained in cases where ligand decomposition took place and sulfur was retained on the catalyst surface.

Recent advances in selective acetylene hydrogenation using palladium containing catalysts

“…The group of Anderson investigated the adsorption of organic sulfur [46][47][48][49] and phosphorous [48][49][50] modifiers on acetylene hydrogenation. Diphenylsulfide and triphenylphosphine were adsorbed onto a Pd/TiO 2 catalyst by impregnation from a hexane solution.…”

CO induced surface segregation as a means of improving surface composition and enhancing performance of CuPd bimetallic catalysts

“…The industrial process typically takes place at low temperature (313-393 K) over a PdAg 'skin' or egg-shell catalyst [25] where Pd is the active metal. The role of Ag is to dilute Pd ensemble size [23] and limit palladium hydride formation [26] which has been shown to be detrimental for achieving high alkene selectivity [27][28][29][30][31][32], although a similar effect may be achieved by using organic sulfur [33][34][35][36] and phosphorous modifiers [33,37]. Several other monometallic [38][39][40], bimetallic [41][42][43][44], trimetallic [45] and metal-free catalysts [46,47] have been shown to offer high alkene selectivity, although they typically require activation and/or use at elevated temperatures.…”

The Modification of Diphenyl Sulfide to Pd/C Catalyst and Its Application in Selective Hydrogenation of p-Chloronitrobenzene

“…Recently, Sajiki's group [14][15][16] produced a series of organic sulfide modified Pd/C catalysts, which moderately depressed the catalyst activity of Pd/C to acquire distinguishing chemoselectivity on hydrogenation. Several studies have revealed that different organic sulfides were able to enhance the selectivity of supported noble metal catalysts in the hydrogenation reactions [7][8][9][15][16][17][18]. However, there is still little information about the effect of organic sulfides on the structure, the adsorption feature and the properties of noble metal catalysts.…”

“…In order to improve the selectivity of the supported noble metal catalysts, many studies have been carried out. The use of carbon monoxide and sulfides as poisons for noble metal catalysts has been recognized as a reasonable method to enhance the selectivity of the catalysts [5][6][7][8][9][10][11][12][13][14][15][16][17]. Supported palladium catalysts modified by CO showed a good performance on the selective removal of acetylene from ethylene rich feeds [5,6].…”

“…For example, sulfide modified noble metal catalysts have been applied to the hydrogenation of halogen-containing aromatic nitro compounds to amines [9,10], selective hydrogenation of acetylene to ethylene [7,8], reductive alkylation of aromatic amines and ketones [11][12][13][14], selective hydrogenation of unsaturated aldehydes/ketones to saturated aldehydes/ketones [15][16][17], and selective hydrogenation of aromatic nitro compounds to aromatic hydroxylamine [18].…”