关键词: 反相微乳化, Pd-Ag双金属催化剂, 纳米颗粒, 乙炔加氢

Abstract: Pd-Ag bimetallic alloy nanoparticles were synthesized by the reverse microemulsion method, and then deposited on Al2O3 to form the supported catalyst. The prepared catalysts showed high activity for selective hydrogenation of acety?lene. The nanoparticles of Pd-Ag and Pd-Ag/Al2O3 samples were characterized by the nanoparticle size analyzer, UV/Vis, HRTEM, EDX, XRD, and XPS. The test results indicated that Pd-Ag bimetallic alloy nanoparticles with a size of about 2 nm and a face-centered cubic (fcc) structure were formed in the measured area of microemulsion. The growth of nanopar?ticles was effectively limited within the droplet of micoremulsion. TEM image exhibited that the Pd-Ag alloy nanoparticles were well-dispersed on the Al2O3 support. The catalytic performance of various catalysts during selective hydrogenation of acetylene showed that a higher acetylene conversion and selectivity to ethylene upon acetylene hydrogenation was achieved on a nano-sized Pd-Ag bimetallic catalyst with a Pd/Ag molar ratio of 1:1.5.

Key words: Reverse microemulsion, Pd-Ag bimetallic catalyst, Nanoparticle, Acetylene hydrogenation