Ni-CeO_(2)/SiO_(2)复合纳米簇催化CO_(2)加氢制甲酸  

Ni-CeO_(2)/SiO_(2)nanoclusters catalyzing CO_(2)hydrogenation to formic acid

作　　者：罗娜娜 刘红[1] 刘思源 张莹[1] 王加升[1] LUO Nana;LIU Hong;LIU Siyuan;ZHANG Ying;WANG Jiasheng(School of Chemical Engineering,Ocean and Life Sciences,Dalian University of Technology,Panjin 124221,Liaoning,China)

机构地区：[1]大连理工大学化工海洋与生命学院,辽宁盘锦124221

出　　处：《精细化工》2025年第3期587-593,共7页Fine Chemicals

基　　金：国家自然科学基金项目(22278063)。

摘　　要：为制备活性高、易分离且成本低的Ni基多相催化剂,以六水合硝酸镍和六水合硝酸铈为原料、自制纳米SiO_(2)为载体,采用反相微乳液法制备了Ni-CeO_(2)/SiO_(2)催化剂,通过SEM、TEM、XRD和XPS对其微观形貌、结构组成、粒径分布和电子结构进行了表征。将Ni-CeO_(2)/SiO_(2)用于催化CO_(2)加氢制备甲酸的反应,考察了反应条件对甲酸产率的影响。结果表明,Ni-CeO_(2)/SiO_(2)呈球形,形貌规整,平均粒径为(60.7±2.6)nm,活性组分Ni-CeO_(2)平均粒径为(1.5±0.4)nm,属于纳米簇;Ni-CeO_(2)/SiO_(2)的Ni、Ce负载量(以SiO_(2)质量计,下同)分别为2.5%和2.1%,比表面积为453 m^(2)/g;在浓度为0.1 mol/L的KHCO_(3)水溶液为CO_(2)源、反应温度200℃、反应时间2 h、氢气压力3 MPa的条件下,Ni-CeO_(2)/SiO_(2)催化CO_(2)加氢制备甲酸的最高产率为77.8%。CeO_(2)的掺杂可促进Ni的分散,且由于Ni与CeO_(2)材料之间功函数的差异,吸引Ni的电子,产生由Ni流向CeO_(2)的电子转移,形成Ni^(δ+)-(CeO_(2))^(δ−)异质结,诱导H2异裂,从而提高Ni-CeO_(2)/SiO_(2)的催化活性。In order to prepare Ni-based heterogeneous catalyst with high activity,easy separation and low cost,Ni-CeO_(2)/SiO_(2)catalyst was synthesized by reverse microemulsion method with nickel nitrate hexahydrate and cerium nitrate hexahydrate as raw materials and self-made nano-SiO_(2)as support,characterized by SEM,TEM,XRD,and XPS for analyses on the microstructure,composition,particle size distribution and electronic structure,and further used to catalyze the hydrogenation of CO_(2)to formic acid,with the effect of reaction conditions on formic acid yield evaluated.The results showed that Ni-CeO_(2)/SiO_(2)exhibited a regular spherical morphology,an average particle size of(60.7±2.6)nm,and the active component Ni-CeO_(2)of(1.5±0.4)nm,which belonged to nanoclusters.The Ni and Ce loading(based on the mass of SiO_(2),the same below)of Ni-CeO_(2)/SiO_(2)were 2.5%and 2.1%,respectively.The specific surface area was 453 m^(2)/g.The formic acid yield reached 77.8%with 0.1 mol/L aqueous solution of KHCO_(3) as CO_(2)source at 200℃and hydrogen pressure 3 MPa in 2 h.The introduction of CeO_(2)promoted the dispersion of Ni,also induced the electron transfer from Ni to CeO_(2)due to the difference of work function between Ni and CeO_(2),forming a Ni^(δ+)-(CeO_(2))^(δ−)hetero junction which could induce the H2 heterocleavage,thereby improving the catalytic activity of Ni-CeO_(2)/SiO_(2).

关 键 词：二氧化碳 甲酸 催化加氢 NI基催化剂 纳米簇 

分 类 号：O643.36[理学—物理化学] TQ225.1[理学—化学]