Activity and sulfur resistance of co-impregnated bimetallic PdNi/γ-Al2O3 catalysts during hydrogenation of styrene

Abstract

Pyrolysis gasoline (PyGas) is an unstable byproduct of the pyrolysis of naphtha and other hydrocarbons for the production of olefins. PyGas is stabilized by hydrogenation at mild conditions. The hydrogenation of styrene to ethylbenzene is considered a model test reaction for studying the selectivity of the catalysts because it has the slowest rate of conversion. The catalytic activity and selectivity of two bimetallic coimpregnated Pd-Ni catalysts supported on γ-alumina were assessed and compared to those of a commercial monometallic Pd catalyst (AXENS LD265). The laboratory-prepared catalysts had different metal content and Pd:Ni atomic ratios (1:1 and 1:7). Catalytic tests of selective hydrogenation of styrene to ethylbenzene were made in a batch stirred tank reactor and in a continuous fixed bed trickle bed reactor. The sulfur resistance of the bimetallic catalysts in semicontinuous condition, was assessed by means of the same operational conditions using thiophene as a model poison compound. The support, Pd-Ni coimpregnated catalysts and LD265 commercial catalysts were further characterized by N 2 chemisorption,

Pd/N, S co-doped activated carbon as a highly-efficient catalyst for the one-pot synthesis of meropenem

“…Therefore, Pd δ + species are more sulfur-resistant than Pd 0 in Pd catalysts. 56–58 The higher the sulfur-doping content of the AC support, the more Pd metal there is in the electron-deficient valence state in the corresponding Pd/C catalyst. The Pd/C4 and Pd/C5 catalysts showed a significantly increased Pd 2+ content compared to the catalysts with less sulfur doping.…”