| Gold catalysts supported on porous carbon are applied to selective oxidation and hydrogenation, showing a better selectivity and poisoning resistance than Pt catalysts. While gold catalysts have a poor affinity with the carbon carrier, and they reunite easily in the preparation process. What’s more, it could make catalytic activity lower when the catalysts leach in the reaction. In addition, sulfur compound can poison gold catalysts, which is one of the obstacles for application. Therefore, we synthesized a gold catalyst using thiol functionalized mesoporous polymer as the support in this work. We selected nitro-phenol reduction as a model, studying the effect of S content on catalytic properties and investigating the resistance of gold catalyst.First of all, we selected thiol functionalized mesoporous polymer as the carrier. It will make gold catalysts stable due to the interaction between gold and sulfur. We studied the effect of pyrolysis on the size of gold nanoparticles and sulfur content. From XRD and TEM results, we found that the material is an ordered mesoscopic structure. The size of gold catalyst is only 3.1 nm even the pyrolytic temperature is 600 ℃. Elemental analysis, ICP-AES and XPS results showed that S content decreased gradually(mass fraction from 9.2% to 0.7%) when the pyrolytic temperature increased due to the removal of SO2 and other molecules. Meanwhile, gold content increased(mass fraction from 1% to 1.4%) during the pyrolysis mainly due to small molecule removal from the support during the carbonizing process. Further studies about the effect of S content on catalytic activity have been done. The results showed that S content of gold catalyst has no influence on TOF when excessive sodium borohydride as a reductant. Au-SH-OMC-as-made(S:Au=63:1) has a TOF of 4.3 min-1, which is the equivalent of the gold catalyst after calcination of removing S. The main reason why catalytic activity decreased is the carbon species during the pyrolysis deposited on the surface of catalyst. It can improve the catalytic activity by a higher pyrolytic temperature or a longer pyrolytic time.In addition, anti-toxicity of gold catalysts was also studied. We used many poisoning agents, such as thiourea, sodium thiocyanate, propanethiol and dodecanethiol as sulfur content agents and quinoline as a nitrogen-poisoning agent. We analyzed the results systematically from solubility, concentration, geometric effect and electronic effect. Poisoning reagents with a high solubility in water like CN2H4 S and NaSCN showed a better resistance in toxicity than poisoning reagents with a low solubility in water like C3H8 S, C12H26 S and C9H7 N. The catalysts with high content of S have a worse resistance. A longer carbon chain of mercaptan can make catalysts poisoned worst due to a strong adsorption and a space steric effect. Nitrogen has a weaker coordination effect than sulfur which leads to a weak degree of quinoline poison. Catalysts with a high content of sulfur showed the most severe degree of poison. Catalysts without sulfur have the highest resistance to toxicity. Even if added CN2H4S(CN2H4S:nAu=40:1), there is no poisoning on catalysts.
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