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甲酸分解制氢是解决能源问题的有效途径,与Pd催化剂相比,Au催化剂不易失活,具有较好的稳定性.使用次亚磷酸钠原位还原制备了Au-P/SiO_2催化剂,并利用X射线衍射、透射电子显微镜和X射线光电子能谱等表征手段探讨其结构,并以甲酸分解为目标反应研究其催化性能.结果表明,该方法制备的催化剂中Au粒子(粒径3nm左右)均匀分散在SiO_2表面,且P掺杂进入Au的晶格形成Au-P复合物,改变了Au的电子结构.同时反应过程中产生的PⅢ被Au3+氧化生成磷酸金,提供酸性中心,使Au-P/SiO_2催化剂表现出较Au/SiO_2催化剂更加优越的催化性能.在363K,4mol/L的甲酸溶液中,Au-P/SiO_2催化剂催化甲酸分解的转化率可达51%,是未掺杂的Au/SiO_2催化剂的4倍.
Formic acid decomposition of hydrogen is an effective way to solve the energy problem, compared with the Pd catalyst, the Au catalyst is not easy to inactivate and has good stability.Using sodium hypophosphite in-situ reduction prepared Au-P / SiO 2 catalyst, X-ray diffraction, transmission electron microscopy and X-ray photoelectron spectroscopy were used to characterize the structure of the catalyst. The catalytic performance of the catalyst was studied by the decomposition of formic acid. The results showed that the average particle size of the Au particles (about 3 nm) Dispersed in the surface of SiO_2, and P doping into the lattice of Au to form Au-P complex, changing the electronic structure of Au. At the same time, PⅢ produced during the reaction is oxidized by Au3 + to form phosphoric acid gold to provide an acidic center. Au- / SiO 2 catalyst shows more superior catalytic performance than Au / SiO 2 catalyst.At 483K, 4mol / L formic acid solution, the conversion rate of Au-P / SiO 2 catalyst for formic acid decomposition up to 51%, is undoped Au / SiO 2 catalyst 4 times.