Enhancement of the Stability of Au-Cu/AC Acetylene Hydrochlorination Bimetallic Catalyst with Melamine Treated Support

This paper highlights the experimental and theoretical studies on the Melamine treated Active Carbon (MAC) support for an Au-Cu bimetallic catalyst in acetylene hydrochlorination reaction. Compared to the original Active Carbon (AC) loaded with the same amount of 0.1wt% Au and 1.0wt% Cu, MAC supported catalyst (MACH), where in Carbon/C6H6N6 mass ratio was 5:3, exhibited excellent catalytic activity. The initial conversion of acetylene increased from 77.5% to 82.7% at 150 ℃ and atmospheric pressure. The gas hourly space velocity (GHSV) was 120 h-1 under a feed volume ratio VHCl/VC2H2 of 1.05. As polymerization of acetylene on the catalyst was the main cause of deactivation, accelerated deactivation test was carried out. The result indicated MACH performed good anti-coking capacity. Based on the characterization by using BET, XRD, SEM, TGA, TPD and XPS techniques, the variation of O1s XPS spectra of the synthesized catalysts was observed that was in line with DFT results. It is postulated that the better stability and the better dispersion of gold cations were ascribed to the additional metal and the modified substrate. The electron transmission from the auxiliary and the elevated groups on the catalyst surface partially inhibited the reduction of the Au3+ active species. Meanwhile, the stronger adsorption energy of HCl was also beneficial to catalytic activity and stability.