Ni/TiB_(2)的制备及催化甲酸制氢性能

Preparation of Ni/TiB_(2) and its property to catalyze formic acid and produce hydrogen

针对催化剂硼化钛(TiB_(2))催化甲酸制氢效率低、催化剂成本高的问题,以TiB_(2)为载体,经浸渍法制备由Ni和TiB_(2)合成的复合催化剂,并通过优化制备工艺提升Ni/TiB_(2)的催化甲酸制氢性能。利用TEM、XRD、XPS等表征方法分析Ni/TiB_(2)的形貌、结构和成分,考察Ni/TiB_(2)催化甲酸制氢性能。结果表明:当煅烧温度为600℃、Ni与TiB_(2)质量比为1∶20时,Ni/TiB_(2)具有Ni芯封装的核壳结构且Ni均匀地分散在TiB_(2)表面,其中Ni与TiB_(2)之间存在电子相互作用。相比于TiB_(2),Ni/TiB_(2)活化能从51.8kJ/mol下降至41.4kJ/mol;当甲酸浓度为10mol/L、反应温度为25℃时,Ni/TiB_(2)最佳催化周转频率(TOF)可达5.85h^(-1),为纯TiB_(2)的292倍。催化甲酸制氢性能的提高,得益于Ni/TiB_(2)催化剂中Ni和TiB_(2)之间的金属-载体强相互作用(SMSI)。研究结果为过渡金属硼化物基催化剂应用于氢能源领域提供了新思路。

In view of the problems of low formic acid catalyzation and hydrogen production efficiency and high catalyst cost of the catalyst titanium boride(TiB_(2)),a composite catalyst synthesized by Ni and TiB_(2)was prepared by means of impregnation,with TiB_(2)as the carrier.The property of Ni/TiB_(2)to catalyze formic acid and produce hydrogen was improved through the optimized preparation process.The morphology,structure and composition of Ni/TiB_(2)were analyzed by TEM,XRD,XPS and other characterization methods,and the property of Ni/TiB_(2)to catalyze formic acid and produce hydrogen was investigated.The results showed that when the calcination temperature was 600℃and the mass ratio of Ni to TiB_(2)was 1∶20,Ni/TiB_(2)had a core-shell structure where the Ni was coated by boride layers,Ni was uniformly distributed on the surface of TiB_(2),and there was an electronic interaction between Ni and TiB_(2).Compared with TiB_(2),the activation energy of Ni/TiB_(2)fell from 51.8kJ/mol to 41.4kJ/mol.When the concentration of formic acid was 10mol/L and the reaction temperature was 25℃,the optimal catalytic turnover frequency(TOF)of Ni/TiB_(2)can reach 5.85h^(-1),which was 292times that of pure TiB_(2).The improved property of Ni/TiB_(2)to catalyze formic acid and produce hydrogen benefited from the strong metal-support interaction(SMSI)between Ni and TiB_(2)in the catalyst Ni/TiB_(2).The research results provide a new idea for the application of transition metal boride-based catalyst in the field of hydrogen energy.