N-doped CoAl oxides from hydrotalcites with enhanced oxygen vacancies for excellent low-temperature propane oxidation  

作　　者：Enhui Wu Daifeng Lin Yinye Chen Xiaoshan Feng Kui Niu Yongjin Luo Baoquan Huang Jianbin Qiu Qingrong Qian Qinghua Chen 

机构地区：[1]Fujian Key Laboratory of Pollution Control&Resource Reuse,Fujian Normal University,Fuzhou 350007,China [2]College of Environmental Science and Engineering,Fujian Normal University,Fuzhou 350007,China

出　　处：《Journal of Environmental Sciences》2022年第6期79-89,共11页环境科学学报（英文版）

基　　金：financially supported by the National Key Research and Development Program of China(No.2019YFC1904500);Young Top Talents of Fujian Young Eagle Program。

摘　　要：A series of nitrogen-doped CoAlO(N-CoAlO)were constructed by a hydrothermal route combined with a controllable NH_(3) treatment strategy.The effects of NH_(3) treatment on the physico-chemical properties and oxidation activities of N-Co AlO catalysts were investigated.In comparison to CoAlO,a smallest content decrease in surface Co^(3+)(serving as active sites)while a largest increased amount of surface Co^(2+)(contributing to oxygen species)are obtained over N-Co AlO/4h among the N-CoAlO catalysts.Meanwhile,a maximum N doping is found over N-CoAlO/4h.As a result,N-CoAlO/4h(under NH_(3) treatment at 400℃ for 4 hr)with rich oxygen vacancies shows optimal catalytic activity,with a T90(the temperature required to reach a 90% conversion of propane)at 266℃.The more oxygen vacancies are caused by the co-operative effects of N doping and suitable reduction of Co^(3+) for NCoAlO/4h,leading to an enhanced oxygen mobility,which in turn promotes C_(3)H_(8) total oxidation activity dominated by Langmuir-Hinshelwood mechanism.Moreover,in situ diffuse reflectance infrared Fourier transform spectroscopy(DRIFTs)analysis shows that N doping facilities the decomposition of intermediate species(propylene and formate)into CO_(2)over the catalyst surface of N-CoAlO/4h more easily.Our reported design in this work will provide a promising way to develop abundant oxygen vacancies of Co-based catalysts derived from hydrotalcites by a simple NH_(3) treatment.

关 键 词：Hydrotalcite derived oxides Propane oxidation N doping Co species Oxygen vacancies 

分 类 号：X701[环境科学与工程—环境工程] O643.36[理学—物理化学]