碳纳米管负载/促进Cu-Cr催化剂上甲醇分解制氢  

Production of H_2 from Decomposition of CH_3OH over CNT-supported/promoted Cu-Cr Catalyst

作　　者：陈书贵[1] 周金梅[1] 张鸿斌[1] 林国栋[1] 蔡启瑞[1] 

机构地区：[1]厦门大学化学化工学院固体表面物理化学国家重点实验室,福建厦门361005

出　　处：《厦门大学学报（自然科学版）》2003年第2期133-138,共6页Journal of Xiamen University：Natural Science

基　　金：国家自然科学基金(50072021);教育部科技基金(20010384002);福建省自然科学基金(2001H017)资助

摘　　要：用自行制备的碳纳米管(CNTs)作为载体,研制出一类高活性CNTs负载/促进甲醇分解制氢Cu Cr/CNTs催化剂.实验结果显示,在0.1MPa,503K,n(CH3OH) n(Ar)=2 1,GHSV=3600h-1的反应条件下,27%Cu10Cr1/CNTs催化剂上H2的时空产率达133mmol H2h-1(g catal.)-1,是AC、SiO2和γ Al2O3负载相应参比催化剂(分别为:111、73.5、60.9mmol H2h-1(g catal.)-1)的1.20、1.81和2.18倍.实验表征研究揭示,碳纳米管载体促使催化剂活性Cu表面积大为增加,并诱使Cu Cr催化活性位上甲醇分子解离下来的吸附H物种向碳纳米管载体"溢流"、疏散、随后偶联成H2(a)脱附,于是降低了副产物甲醛、甲酸甲酯的生成机率,有利于提高甲醇深度脱氢、生成H2和CO的选择性.With a kind of multiwalled carbon nanotubes (CNTs) synthesized catalytically inhouse and the nitrates of the corresponding metallic components, highly active CNTsupported and promoted catalysts, wt%CuiCrj/CNTs, were prepared by an incipient wetness method, and their catalytic performance for production of H2 from decomposition of CH3OH was investigated and compared with the corresponding those supported by AC, SiO2 and γAl2O3. It was experimentally found that the support could significantly affect the catalyst activity for methanol decomposition. Over a 27%Cu10Cr1/CNTs catalyst, spacetimeyield of H2 reached 133 mmolH2 h-1 (gcatal.)-1 under reaction condition of 0.1 MPa, 503 K, n(CH3OH)n(Ar)= 21, GHSV= 3 600 h-1, which was 1.20, 1.81 and 2.18 times as high as those of the reference systems supported by AC, SiO2 and γAl2O3 at the same reaction condition, respectively. The nature of promoter action by the CNTs was discussed together with the results of characterization study of the CNTcarrier and the CNTsupported catalysts by TEM, XRD, TPR, TPD and Cu exposed area. The results indicated that the CNTs served not only as a carrier, but also as an excellent dispersant for CuCr2O3 components, which led to a significant increase of the Cu exposed area, generating more catalytically active Cusites at the catalyst surface for methanol decomposition. On the other hand, the CNTs could serve as an excellent promoter for 'hydrogen spillover' from the catalytically active sites of CuCr to CNTcarrier, which would be conducive to scattering hydrogenadspecies produced from dehydrogenation of methanol molecules at CuCr sites and transferring them to the CNT carrier, followed by the coupling and desorption, thus favorable to reducing the probability of formation of the byproducts, formaldehyde and methylformate, and enhancing the selectivity of deep dehydrogenation of methan

关 键 词：Cu—Cr催化剂 碳纳米管载体 碳纳米管促进剂 甲醇 氢气 氢能 催化分解 

分 类 号：TQ116.2[化学工程—无机化工] TQ032.4