构筑可控催化氧化性能催化剂用于醇的转化

通过金属离子替代的方法设计了催化氧化性能不同的Mg-Al-Ru-CO₃类水滑石、Co-Al-Ru-CO₃类水滑石和Ru-Co(OH)₂-CeO₂等三种催化剂. XRD实验表明钌部分替换制得的Mg-Al-Ru-CO₃和Co-Al-Ru-CO₃可保持水滑石的结构; 但用铈替代铝之后得到的Ru-Co(OH)₂-CeO₂催化剂无法保持水滑石的结构， 而是由氢氧化钴和二氧化铈的微晶组成. XPS 和Ru K-edge XAFS的测试结果证实Mg-Al-Ru-CO3催化剂中钌被等键长的6个氧原子包围， 该催化剂可有效地催化氧化醇类； Co-Al-Ru-CO₃催化剂中钌被两种键长不等的6个氧原子包围， 其中短键长的Ru═O是催化氧化性能增强的原因； Ru-Co(OH)₂-CeO₂催化剂中钌被两种键长不等的5个氧原子包围， 其对于各类醇均有高效的催化氧化性能， 原因归功于配位数少的钌物种.

Development of Catalysts with Tunable Catalytic Oxidative Performance for Alcohols Conversion

The catalytic oxidative performance of Mg-Al-Ru-CO3 hydrotalcite,Co-Al-Ru-CO3 hydrotalcite, Ru-Co(OH)2-CeO2 was well designed and tuned with substitution method.The XRD characterization presented that both the Mg-Al-Ru-CO3 catalyst and Co-Al-Ru-CO3 catalyst could keep hydrotalcite structure after the partial sub-stitution of Al with Ru. However,after the substitution of Al with Ce, the structure of the obtained Ru-Co(OH)2-CeO2 catalyst was microcrystals of cobalt hydroxide and cerium oxide. The results of XPS and Ru K-edge XAFS suggested that the isolated Ru atom in Mg-Al-Ru-CO3 hydrotalcite was surrounded by 6 oxygen atoms with only one type of Ru-O shells, which catalyzed alcohols oxidation efficiently; the isolated Ru atom in Co-Al-Ru-CO3 hydrotalcite was surrounded by 6 oxygen atoms with two types of Ru-O shells, therein unsaturated Ru=O double bond was responsible for higher catalytic efficient for alcohols oxidation; the isolated Ru atom in Ru-Co(OH)2-CeO2 catalyst surrounded by 5 oxygen atoms with two types of Ru-O shells, therein the unsaturated coordination of Ru was the key to attain higher ability for various kinds of alcohols oxidation.