改性硼酸钴催化剂的制备及其丙烷氧化脱氢性能研究  

Research on preparation of modified cobalt borate catalysts and their performances in oxidative dehydrogenation of propane

作　　者：钱贺明 穆晓亮 房克功[1] QIAN Heming;MU Xiaoliang;FANG Kegong(State Key Laboratory of Coal Conversion,Institute of Coal Chemistry,Chinese Academy of Sciences,Taiyuan 030001,Shanxi,China;Petro China Dagang Petrochemical Company,Tianjin 300270,China)

机构地区：[1]中国科学院山西煤炭化学研究所煤转化国家重点实验室,山西太原030001 [2]中国石油大港石化公司,天津300270

出　　处：《低碳化学与化工》2023年第1期80-87,共8页Low-Carbon Chemistry and Chemical Engineering

基　　金：山西省自然科学基金(201901D111457)。

摘　　要：采用共沉淀法结合物理研磨法制备了一系列不同钴含量的改性硼酸钴(CoB4O7)催化剂。丙烷氧化脱氢反应结果显示,改性硼酸钴催化剂的活性随着钴含量的增加呈现先升高后降低的趋势。在反应温度为480℃的温和反应条件下,钴负载量(质量分数)为30%的催化剂具有最高的丙烷转化率(20.1%)和轻质烯烃(C_(2)=和C_(3)=)选择性(86.7%)。结合催化剂的表征结果,认为向CoB_(4)O_(7)前驱体引入适量的钴可以增加催化剂的表面积和表面电子密度,有利于催化剂暴露更多的活性位点,增强催化剂对氧气的吸附活化能力;而添加过量的钴会导致BO_(4)和晶格氧(M—O)组分增多,促进丙烷的裂解并降低轻质烯烃选择性。A series of modified cobalt borate(CoB4O7) catalysts with different cobalt contents were prepared by coprecipitation combined with physical grinding method. In the test of oxidative dehydrogenation of propane, it shows that the activity of modified cobalt borate catalysts increases first and then decreases with the further increase of cobalt content. Under the mild reaction temperature of 480 ℃, the catalyst with 30% cobalt loading(mass fraction, same below) has the highest propane conversion rate(20.1%) and light olefin(C_(2)= and C_(3)=) selectivity(86.7%). Combined with the characterization results of the catalysts, it is concluded that the introduction of appropriate amount of cobalt into CoB_(4)O_(7) precursor can increase the surface area and surface electron density of the catalyst, which is beneficial to expose more active sites and enhance its adsorption and activation ability for oxygen. However,the addition of excess cobalt will lead to the increase of BO4and M—O components, promote propane cracking and reduce light olefin selectivity.

关 键 词：丙烷 氧化脱氢 硼酸钴 钴含量 

分 类 号：TQ221.2[化学工程—有机化工] TQ426