Production of ethanol by gas phase hydrogenation of acetic acid over carbon nanotube-supported Pt–Sn nanoparticles

Supported bimetallic Pt–Sn catalysts with different carriers were prepared through a one-step reduction method for the gas phase hydrogenation of acetic acid to ethanol. The structure of the catalysts was characterized by X-ray diffraction, transmission electron microscopy and energy-dispersive X-ray spectroscopy. Among these catalysts, the carbon nanotube-supported bimetallic Pt–Sn catalyst (Pt–Sn/CNT) showed the best performance, exhibiting over 97% conversion and 92% selectivity to ethanol under relatively mild conditions. The addition of Sn to Pt catalyst inhibited the Csingle bondC bond cleavage activity and enhanced the selectivity of the catalyst to ethanol, due to the formation and well-dispersion of PtSn alloy on the CNT surfaces. The catalytic performance depended on the ratio of Sn and Pt and the particle size of PtSn alloy. The one-step reduction method was conductive to preparing catalyst with smaller PtSn alloy particles and higher performance, which was shown that the optimized Pt–Sn/CNT with average PtSn alloy particle size at 3.0 nm can retain its high catalytic performance for over 300 h on stream.