| Paper Name |
Mechanism of sulfur poisoning to Ru-based catalysts in supercritical water gasification of glycerol: From experiment to combined DFT and kinetics studies |
| Author |
Xinyu Cui, Haoran He, Dan Xie, Lixiao Zheng, Xuebin Wang*, Zhao Jiang, Donghai Xu, Yang Guo* |
| Publication/Completion Time |
2023-03-24 |
| Magazine Name |
Chemical Engineering Journal |
| Vol |
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| Related articles |
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| Paper description |
Sulfur species are an inevitable hazardous component in biomass that may significantly deactivate noble metal catalysts thus limit H2 generation during supercritical gasification process of biomass. However, the mechanism of catalyst sulfur poisoning under hydrothermal conditions remains unclear. Herein, we carried out systematic experimental and kinetic studies to investigate the effect of sulfur toxicity on the performance of Ru-based catalysts in supercritical water gasification of glycerol. Sulfur significantly affected the catalytic performance for the water-gas shift reaction due to its competitive adsorption with CO. Consequently, CO increased with increasing sulfur concentrations while H2 gradually decreased. Density functional theory calculations confirmed that the adsorption energy of CO at Ru and Ni surfaces tends to decrease in the presence of surface S, thus promoting CO desorption. A kinetic model involving the adsorption and desorption process was developed based on a proposed reaction network and the calculation provides clear evidence for experimental observation that the CO adsorption rate decreases with increasing sulfur concentration, from 9.36×10-2 to 6.24×10-2 L2·mol-1·min-1·gcat-1, while desorption rate rises, from 5.20×10-3 to 1.56×10-1 L2·mol-1·min-1·gcat-1. Due to the competing adsorption of sulfur and CO, the reaction rate analysis revealed that the CO methanation reaction had a greater impact on the rate of CO consumption than the adsorption-desorption process. |
(创新港)
