Selective Hydrogenation of Acetylene over Pd-In/Al₂O₃ Catalyst: Promotional Effect of Indium and Composition-Dependent Performance

Abstract

Highly dispersed bimetallic Pd-In catalysts on Al 2 O 3 were prepared by a simple impregnation method. In comparison with the unsupported intermetallic catalyst, the supported Pd-In catalyst exhibited several magnitudes higher activity and similar selectivity for selective acetylene hydrogenation. Moreover, the activity, selectivity, and anticoking performance of the Pd-In catalyst were superior to those of the monometallic Pd catalyst. The electron transferred from indium weakened the adsorption of ethylene on the negatively charged Pd sites and hence improved the selectivity of Pd-In/Al 2 O 3 . The inhibited formation of hydride due to the presence of indium also contributed to the higher selectivity. The promoted activation of hydrogen, owing to the weak adsorption of acetylene on Pd-In/Al 2 O 3 , and decreased particle size jointly contributed to the enhanced activity of Pd-In/Al 2 O 3 . In addition, green oil formation on Pd-In/Al 2 O 3 was retarded by the presence of indium, contributing to the enhanced stability of the catalyst. The bimetallic Pd-In catalysts showed a strongly composition dependent performance, which resulted from the different extent of electronic and/or geometric modification of Pd active sites.

Highly-Ordered PdIn Intermetallic Nanostructures Obtained from Heterobimetallic Acetate Complex: Formation and Catalytic Properties in Diphenylacetylene Hydrogenation

“…77 °C (profile 1). The data are in good agreement with previously reported results [ 51 , 52 , 53 , 54 ]. The ratio of H/Pd was calculated to be 0.32, and this small value can be explained by the relatively low hydrogen partial pressure since 5% H 2 /Ar mixture was used.…”

Enhanced catalytic performance of Pd‐Ga bimetallic catalysts for 2‐ethylanthraquinone hydrogenation

“…In situ CO‐DRIFTS was performed to investigate the geometric and electronic structure of the catalysts . As displayed in Figure , the 0.6Pd and 0.6Pd1.2Ga catalysts exhibit two adsorption peaks at 2015–2150 cm −1 and 1900–1950 cm −1 , corresponding to the linear bonded CO and the bridge bonded CO, respectively . Table lists the integral peak area of the two bonds.…”

Pure Acetylene Semihydrogenation over Ni–Cu Bimetallic Catalysts: Effect of the Cu/Ni Ratio on Catalytic Performance

“…Two significant weightlessness peaks appeared for all catalysts. The weightlessness at low temperature (210-390 • C) can be attributed to the combustion of light hydrocarbons adsorbed in the catalyst pores or on the catalyst surface [34,35], whereas the weightlessness at high temperature (>390 • C) is attributable to the combustion of heavy hydrocarbons or coke deposited on the catalyst surface [36,37]. Note that compared with the Ni catalyst, the weightlessness peak significantly moved toward the high temperature region after adding Cu, which indicates that the green oil deposits changed to hydrocarbons heavier than those deposited on the Ni catalyst surface.…”