Boron-modified activated carbon supporting low-content Au-based catalysts for acetylene hydrochlorination

A series of boron-modified low-gold-content Au-based catalysts were prepared by impregnation. Characterization by N-2 adsorption/desorption, XPS, H-2-TPR, HCl/C2H2-TPD, TG, TEM, and SEM was applied to analyze the catalyst. Compared with the unmodified catalyst, B-modified Au0.25%/BAC-20% exhibited better performance (acetylene conversion increase by 21.4% and selectivity to VCM of more than 99.5%) at a space velocity of 770 h(-1) and 150 degrees C. The results indicated that the presence of boron species is favorable to the stabilization of catalytically active Au3+ species and the inhibition of Au3+ to Au-0 during acetylene hydrochlorination, and hence improves the catalytic stability. In addition, the presence of boron species can effectively inhibit carbon deposition and also inhibit the catalyst sintering during the reaction. TPD experiments revealed that not the adsorption ability of C2H2 but the adsorption ability of the HCI played a crucial role in boron-modified Au-based catalysts. (C) 2016 Published by Elsevier Inc.