V^(4+)和V^(5+)比例对钒磷氧催化NO2氧化环己烷性能的影响  

Correlation with the redox V^(4+)/V^(5+)ratio in VPO catalysts for oxidation of cyclohexane by NO_(2)

作　　者：蹇建 张嘉明 佘祥 周虎[1] 游奎一[2] 罗和安[2] JIAN Jian;ZHANG Jiaming;SHE Xiang;ZHOU Hu;YOU Kuiyi;LUO Hean(School of Chemistry and Chemical Engineering,Hunan University of Science and Technology,Xiangtan 411201,Hunan,China;School of Chemical Engineering,Xiangtan University,Xiangtan 411105,Hunan,China)

机构地区：[1]湖南科技大学化学化工学院,湖南湘潭411201 [2]湘潭大学化工学院,湖南湘潭411105

出　　处：《化工学报》2023年第4期1570-1577,F0002,共9页CIESC Journal

基　　金：国家自然科学基金项目(22202068);湖南省自然科学基金项目(2021JJ30239);湖南省重点研发计划项目(2019GK2041)。

摘　　要：采用浸渍法制备不同钒价态结构的钒磷氧(VPO)复合氧化物催化剂,测试其对NO_(2)氧化环己烷制备己二酸的催化性能,并采用XRD、XPS、H2-TPR和UV-Vis DRS等手段进行表征,考察不同过渡金属掺杂对VPO中钒价态结构的影响,以及催化氧化环己烷性能的影响。研究结果表明,过渡金属的引入能够改变VPO中β-VOPO4和(VO)_(2)P_(2)O_(7)两种晶相结构,从而调变V^(5+)和V^(4+)的比例,且钒的价态比例对NO_(2)氧化环己烷反应具有重要影响。同时含有V^(5+)和V^(4+)的M/AlVPO催化剂的催化性能明显高于纯V^(5+)的β-VOPO4和纯V^(4+)的(VO)_(2)P_(2)O_(7)催化剂。其中,以V^(4+)/V^(5+)为0.52的Cu/AlVPO为催化剂时环己烷的转化率最高为65.4%,以V^(4+)/V^(5+)为0.66的Ni/AlVPO为催化剂时己二酸的选择性最高为84.8%。Vanadium phosphorus oxide(VPO)catalysts doped with different transition metals were prepared by impregnation method,and their catalytic performance for cyclohexane oxidation by NO_(2)to adipic acid were tested.The XRD,XPS,H2-TPR and UV-Vis DRS were used to investigate the effect of transition metal doping on the valence structure of vanadium in VPO catalysts and the catalytic performance for oxidation of cyclohexane.The results showed that the introduction of transition metals could change the phase structure ratio ofβ-VOPO4 and(VO)_(2)P_(2)O_(7)in VPO samples,thus changing the ratio of V^(5+)and V^(4+).In addition,the valence structure of vanadium in VPO catalysts played an important effect in the oxidation of cyclohexane to adipic acid by NO_(2).The catalytic performance of M/AlVPO catalyst containing both V^(5+)and V^(4+)was significantly higher than that of the pure V^(5+)β-VOPO4 and pure V^(4+)(VO)_(2)P_(2)O_(7)catalysts.Among them,when Cu/AlVPO with V^(4+)/V^(5+)of 0.52 was used as the catalyst,the conversion rate of cyclohexane was 65.4%,and the selectivity of adipic acid was 84.8%when Ni/AlVPO with V^(4+)/V^(5+)of 0.66 was used as the catalyst.

关 键 词：钒磷氧复合氧化物 环己烷 己二酸 催化氧化 催化机理 

分 类 号：TQ235[化学工程—有机化工]