Green Preparation Of Activated Carbon Fibers Supported Gold Catalysts And Study On Catalytic Performance Of Acetylene Hydrochlorination

Au catalysts supported with carbon-based carriers have been extensively studied for the hydrochlorination of acetylene and were expected to replace the industrial toxic mercury catalysts.However,the removal of the highly corrosive aqua regia used in the preparation of carbon-based catalysts while maintaining catalytic activity and stability remains a key challenge.In this paper,the carriers'characteristics of gold/carbon catalyst for acetylene hydrochlorination were screened and studied,and the influence of pore structure parameters and different surface properties on different carbon supported Au catalysts were analyzed and further studied the reaction theory of Au/ACF-H₂O catalyst.The main work and conclusions are as follows:?1?The evaluation result illustrated that the Au/ACF-H₂O catalyst was superior to other carbon supported catalysts in both activity and stability.The characterization and analysis showed that ACF has higher specific surface area and microporous structure was more developed.The cationic gold?AuCl_x?species were highly dispersed on the surface of ACF,and the content and reduction temperature were higher than the other catalysts.It is speculated that was related to its special surface chemistry properties.Furthermore,the properties of Au/ACF-H₂O catalysts were investigated under different process parameters.The optimal reaction conditions were:temperature=180°C,P=0.1 MPa and V?HCl?/V?C₂H₂?=1.2,GHSV?C₂H₂?=1480h^-1,Au/ACF-H₂O catalyst can maintain high activity and stability within 10 h,which paved the way for further research on the reaction theory.?2?The characterization results showed that Au species were mainly appear as isolated atoms on the surface of ACF and and its content and reduction temperature were significantly higher than acid-treated activated carbon carrier.From the surface properties of the carrier,the result illustrated that the Au/ACF-H₂O catalytic properties could be attributable for the anchoring and stabilization for gold active species on SOGs of higher amount of phenol and carbonyl groups as well as lower amount of carboxyl,carboxylic anhydride,and lactones groups,and for the improvement of HCl adsorption with the synergistic effect of electron-donating pyrrolic N species.The performance evaluation and comparison results show that Au/ACF-H₂O catalytic exhibited stronger catalytic activity and stability than Au/ROX0.8?AQ?-H₂O.Compared with the typical strong oxidant prepared catalysts,it was performed that the catalytic activity of the Au/ACF-H₂O was relatively lower but the stability was better.This result may be attributed to the higher cationic Au content and the prevalence of atomic dispersion of Au species on catalysts prepared in strong oxidizing agents,which may be superior to that on the catalysts prepared in water.The reason for the superior stability was speculatively based on the influence of surface chemistry and could be attributed to the presence of SOGs and pyrrolic N species which may have served as anchoring sites for Au species on ACF.In general,the development and design of a new green material such as ACF,which could be a substitute for acid-treated activated carbon and reduce/eliminate the use of strong oxidizing reagents,as a catalyst carrier is essential for the sustainable development of the PVC industry.