Silica deposition on the benchmark aqueous phase reforming (APR) catalyst Pt/γ-Al₂O₃ is studied to prevent or limit hydrolytic attack of the support under hydrothermal APR conditions, for which boehmite formation by support hydration is a known cause for catalyst deactivation. Tetraethyl orthosilicate (TEOS) is employed as a silicon source in a straightforward liquid-phase, silylation process followed by catalyst calcination and reduction. Characterization by X-ray diffraction, temperature-programmed desorption of NH₃, infrared, ²⁷Al nuclear magnetic resonance and X-ray photoelectron spectroscopy of the fresh catalysts suggests that silica addition occurs preferentially on the support surface, resulting in weak Brønsted acid sites as well as in the formation of Si-O-Al linkages at the expense of specific surface Lewis acid sites. Silylation and calcination of Pt/γ-Al₂O₃ causes partial blockage of the metal surface area (12% loss), whereas γ-Al₂O₃ surface silica modification prior to Pt deposition makes controlled metal deposition difficult. Catalytic performance tests show the overcoated samples to be active in the APR of 5 wt% glycerol, albeit with lower H₂ production rates compared to the benchmark catalyst. Characterization of spent APR catalysts clearly demonstrates that silylation/calcination treatments effectively slows down the transformation of the γ-Al₂O₃ support due to the formation of a Si-O-Al interface. Overall, the lifetime of the catalyst is increased three-fold as a result of the surface overcoating treatment, with repetitive recycling ultimately leading to loss of the protective silica layer.

基准的水相二氧化硅沉积重整（APR）催化剂的Pt /γ-Al系₂ ö ₃进行了研究，以防止或热液APR条件下支持，为此，勃姆石的形成通过支持水合为催化剂失活一个已知原因的限制水解攻击。正硅酸四乙酯（TEOS）在直接的液相甲硅烷基化过程中用作硅源，然后进行催化剂煅烧和还原。通过X射线衍射，NH ₃的程序升温脱附，红外，²⁷表征新鲜催化剂的Al核磁共振和X射线光电子能谱表明，二氧化硅的添加优先发生在载体表面上，导致弱的布朗斯台德酸位以及形成Si-O-Al键，但以特定的表面为代价路易斯酸位点。甲硅烷基化和Pt的煅烧/γ-Al系₂ ö ₃使金属表面积（12％的损失）的部分堵塞，而在γ-Al ₂ ö ₃表面的二氧化硅改性之前的Pt沉积使得控制金属沉积困难。催化性能测试表明，尽管H ₂含量较低，但包覆涂层的样品在5 wt％甘油的APR中仍具有活性生产率与基准催化剂相比。废催化剂四月表征清楚地表明，甲硅烷基化/煅烧处理有效地将γ-Al的转化变慢₂ ö ₃支持由于在Si-O-A1接口的形成。总体而言，由于表面重涂处理，催化剂的寿命增加了三倍，重复循环最终导致保护性二氧化硅层的损失。