组合型Pt-K-Ce/γ-Al_2O_3催化剂的邻苯基苯酚的催化合成性能

Synthesis of O-phenylphenol with Assembled Pt-K-Ce Catalysts

采用金属有机化合物Pt2(dba)3(dba为二亚苄基丙酮)氢气分解法制备Pt纳米颗粒,直接吸附到K-Ce/γ-Al2O3上制得组合型Pt-K-Ce/γ-Al2O3催化剂。利用透射电子显微镜、X射线衍射、差热-热重对催化剂进行表征。以邻环己烯环己酮(二聚酮)为原料,经组合型催化剂催化合成邻苯基苯酚。在LHSV为0.48 h?1、反应温度355℃、无外加氢气的条件下二聚酮的转化率为98.0%,OPP的选择性达97.7%。催化剂失活的原因有积炭、团聚、氧化铝及CeO2的结构破坏、载体比表面积下降、覆盖等,其中结构破坏和覆盖是催化剂失活的主要原因。

O-phenylphenol （OPP） synthesis using dimers was investigated with assembled Pt-K-Ce/7-A1203catalysts. Pt nanoparticles were obtained by decomposition of Pt2（dba）3（dba=dibenzalacetone） and theassembled catalysts were prepared via attaching Pt nanoparticles directly onto K and Ce modified alumina. Thecatalyst prepared under optimized conditions （0.48 h-1, 355 ℃, H2-free） shows a dimer conversion ratio of 98%and OPP selectivity of 97.7%. Transmission electron microscopy （TEM）, X-ray diffraction （XRD） andThermogravimetTy-Differential Thermal analysis （TG-DTA） were used to characterize the catalysts prepared. Itwas found that catalyst deactivation is caused by coke, glomeration, structure damage, decrease of specific surfacearea and Pt nanoparticle coverage, and Pt nanoparticle coverage and structural damage are the two main factors.