The effects of solvents (n-hexane, isopropanol (IPA), tetrahydrofuran (THF) and methanol) on the hydrogenation of toluene over the Pd/SiO₂ and Ru/SiO₂ catalysts were studied. Microcalorimetric adsorption and IR spectroscopy were employed to understand the effects. It was found that n-hexane adsorbed weakly on the catalysts and thus affected less the hydrogenation of toluene, while THF and methanol adsorbed strongly on the catalysts and inhibited the activity of hydrogenation of toluene significantly. IPA also adsorbed strongly on the catalysts, but it exhibited a hydrogen transfer effect on the surfaces that promoted the conversion of toluene.

中文翻译：

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了解溶剂对负载 Pd 和 Ru 催化剂上甲苯加氢的影响

研究了溶剂（正己烷、异丙醇（IPA）、四氢呋喃（THF）和甲醇）对甲苯在Pd/SiO ₂和Ru/SiO ₂催化剂上加氢的影响。微量热吸附和红外光谱被用来了解影响。发现正己烷对催化剂的吸附较弱，对甲苯的加氢影响较小，而四氢呋喃和甲醇对催化剂的吸附较强，对甲苯的加氢活性有明显的抑制作用。IPA 也强烈吸附在催化剂上，但它在表面上表现出氢转移效应，促进了甲苯的转化。