Reverse Microemulsion Synthesis and Characterization of Pd-Ag Bimetallic Alloy Catalysts Supported on Al2O3 for Acetylene Hydrogenation

摘要

Pd-Ag bimetallic alloy nanoparticles were synthesized by the reverse microemulsion method,and then deposited on Al2O3 to form the supported catalyst.The nanoparticles of Pd-Ag and Pd-Ag/Al2O3 samples were characterized by 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 nanoparticles 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 for 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 alloy supported molar ratio of 1:1.5.