摘要
制备高分散的负载型催化剂是充分利用在自然界中储量极为有限的贵金属资源的重要手段.采用不同方法制备一系列负载Pd催化剂,考察了不同载体负载Pd催化剂的CO氧化性能.发现以乙酰丙酮钯为前驱体制得的Pd/TiO2催化剂活性远高于Pd/SiO2和Pd/Al2O3催化剂的活性,在室温下就表现出较好的CO氧化活性,且在无气相O2条件下CO可以与Pd/TiO2催化剂表面的氧物种(晶格氧)反应生成一定量的CO2.分散度测试、CO吸附的原位红外光谱和程序升温还原的结果表明Pd/TiO2催化剂上Pd物种以高分散Pd0形式存在,并与载体之间存在强相互作用,这可能是Pd/TiO2催化剂具有低温活性的主要原因.
In present studies,a series of oxide supported palladium catalysts were synthesized using various methods to achieve a better dispersion of the active component.CO oxidation was selected as a probe reaction to examine the catalytic performance.It was found that Pd/TiO2 catalyst prepared using palladium（II） acetate as a precursor exhibited high catalytic activity for CO oxidation at room temperature,which activity is much higher than those on Pd/SiO2 and Pd/Al2O3 catalysts.In-situ Fourier transform infrared spectroscopy（FT-IR） reveals that CO can react with surface lattice oxygen of TiO2 to form CO2 in the absence of gas O2 on the Pd/TiO2 catalyst.Comparative studies using BET,O2-chemisorption,in-situ FT-IR of CO adsorption and temperature programmed reduction（H2-TPR） techniques were carried out in order to elucidate the relationship between the structure and activity for CO oxidation at low temperature.Metallic Pd was found to be highly dispersed on TiO2 and Al2O3 support surfaces.A relatively high temperature reduction peak observed in H2-TPR suggests a strong interaction between Pd and the TiO2 support.The origins of the high activity for CO oxidation on Pd/TiO2 at near room temperature may come from the highly dispersive Pd and the strong interaction between Pd and support.
出处
《厦门大学学报（自然科学版）》
CAS
CSCD
北大核心
2011年第1期65-69,共5页
Journal of Xiamen University：Natural Science
基金
国家自然科学基金资助项目(20873109
21073149)
科技部973项目(2010CB732303)
教育部科学技术研究重大项目(309019)
教育部博士点基金(200803841011)
福建省自然科学基金资助项目(2008J0168)
关键词
CO催化氧化
钯
负载型催化剂
原位谱学表征
CO catalytic oxidation
palladium
supported catalysts
in-situ spectroscopy
