溶胶-凝胶法制备高分散Ni-Cu/SiO_(2)促进间甲酚直接脱氧制甲苯  

Highly dispersed Ni-Cu/SiO_(2)synthesized by sol-gel method for prompting direct deoxygenation of m-cresol to toluene

作　　者：王颖杰 祝新利[1] WANG Yingjie;ZHU Xinli(School of Chemical Engineering and Technology,Tianjin University,Tianjin 300072,China)

机构地区：[1]天津大学化工学院,天津300072

出　　处：《化工进展》2024年第7期3824-3833,共10页Chemical Industry and Engineering Progress

基　　金：国家自然科学基金(22278299,21676194)。

摘　　要：在木质素生物质衍生的酚类化合物加氢脱氧生产芳烃中,Ni基催化剂兼具经济性与活性,然而,在温和条件下会受到C—C氢解的影响。在此,采用溶胶-凝胶法制备了高分散的Ni/SiO_(2)、Cu/SiO_(2)和不同Cu含量的双金属Ni-Cu催化剂,并在350℃和常压条件下对其进行间甲酚加氢脱氧性能测试。尽管Ni粒径约为2nm的单金属Ni/SiO_(2)表现出高的活性和甲苯选择性,但C—C氢解生成甲烷和苯的反应仍然显著。对于双金属Ni-Cu催化剂,Ni和Cu相互作用并在还原后形成Ni-Cu合金。在最佳的双金属催化剂(Cu/Ni摩尔比约为3)上,甲苯在所有转化水平上都是主要产物。当间甲酚转化率为97.2%时,甲苯和芳烃的收率分别达到85.0%和91.6%。本征反应速率和活化能分析表明,Cu的引入通过抑制竞争性的C—C氢解反应,促进了直接脱氧生成甲苯。Ni based catalysts are relatively cheap and active for hydrodeoxygenation(HDO)of lignin biomass derived phenolic compounds to produce aromatics,but they suffer from the C—C hydrogenolysis under mild conditions.Herein,highly dispersed Ni/SiO_(2),Cu/SiO_(2)and bimetallic Ni-Cu catalysts with different Cu content were prepared by sol-gel method,and tested for HDO of m-cresol at 350℃and atmospheric pressure.Although bare Ni/SiO_(2)with Ni size of 2nm showed high activity and toluene selectivity,significant C—C hydrogenolysis activity toward CH_(4)and benzene were observed.Ni and Cu in bimetallic Ni-Cu catalysts could interact each other and form Ni-Cu alloy after reduced.Toluene were the dominant product over optimal bimetallic catalyst(Cu/Ni molar ratio of 3)at all conversion levels.At mcresol conversion of 97.2%,the yields of toluene and aromatics reached 85.0%and 91.6%,respectively.Analysis of intrinsic reaction rate and activation energy indicates that the addition of Cu enhances the direct deoxygenation toward toluene by inhibiting the competitive C—C hydrogenolysis reaction.

关 键 词：催化 生物质 再生能源 间甲酚 加氢脱氧 Ni-Cu合金 

分 类 号：TK6[动力工程及工程热物理—生物能] O643.32[理学—物理化学]