title: Synthesis of octahedral, truncated octahedral, and cubic Rh2Ni nanocrystals and their structure-activity relationship for the decomposition of hydrazine in aqueous solution to hydrogen.
abstract: We developed a co-reduction method to synthesize octahedral, truncated octahedral, and cubic Rh2Ni nanocrystals. The shape/size distribution, structural characteristics, and composition of the Rh2Ni nanocrystals are investigated, and their possible formation mechanism at high temperatures in margaric acid/1-aminoheptadecane solution in the presence of tetraethylgermanium and borane trimethylamine complexes is proposed. A preliminary probing of the structure-activity dependence of the surface "clean" Rh2Ni nanocrystals supported on carbon towards hydrazine (N2H4) in aqueous solution dehydrogenation revealed that the higher the percentage of {111} facets, the higher is the activity and H2 selectivity of the nanocrystals. This result was attributed to the {111} facets not only introducing more basic sites, but also weakening the interaction between the produced adspecies (including H2 and NHx) and surface metal atoms in comparison with those of {100} facets. Furthermore, the as-prepared Rh2Ni nanooctahedra exhibited 100% H2 selectivity and high activity at room temperature for H2 generation via N2H4 decomposition. The activation energy of the Rh2Ni nanooctahedra was 41.6 ± 1.2 kJ mol(-1). The Rh2Ni nanooctahedra were stable catalysts for the hydrolytic dehydrogenation of N2H4, providing 27 723 total turnovers in 30 h. Our work provides a new perspective concerning the possibility of constructing hydrogen-producing systems based on N2H4 and surface "clean" Rh2Ni nanocrystal catalysts with defined shapes supported on carbon that possess a competitive performance in comparison with NaBH4 and NH3BH3 hydrogen-producing systems for fuel cell applications.
authors: Mineral Resources Chemistry Key Laboratory of Sichuan Higher Education Institutions, College of Materials and Chemistry & Chemical Engineering, Chengdu University of Technology, Chengdu 610059, China. tongdongge@163.com and Collaborative Innovation Center of Panxi Strategic Mineral Resources Multi-purpose Utilization, Chengdu 610059, China.
authors: Chun
authors: C
authors: Li
authors: Mineral Resources Chemistry Key Laboratory of Sichuan Higher Education Institutions, College of Materials and Chemistry & Chemical Engineering, Chengdu University of Technology, Chengdu 610059, China. tongdongge@163.com and Collaborative Innovation Center of Panxi Strategic Mineral Resources Multi-purpose Utilization, Chengdu 610059, China.
authors: Tao
authors: T
authors: Wang
authors: College of Chemical Engineering and Key Laboratory of Green Chemistry & Technology of Ministry of Education, Sichuan University, Chengdu 610065, China. chuwei1965@foxmail.com.
authors: Wei
authors: W
authors: Chu
authors: Mineral Resources Chemistry Key Laboratory of Sichuan Higher Education Institutions, College of Materials and Chemistry & Chemical Engineering, Chengdu University of Technology, Chengdu 610059, China. tongdongge@163.com and Collaborative Innovation Center of Panxi Strategic Mineral Resources Multi-purpose Utilization, Chengdu 610059, China.
authors: Ping
authors: P
authors: Wu
authors: Mineral Resources Chemistry Key Laboratory of Sichuan Higher Education Institutions, College of Materials and Chemistry & Chemical Engineering, Chengdu University of Technology, Chengdu 610059, China. tongdongge@163.com and Collaborative Innovation Center of Panxi Strategic Mineral Resources Multi-purpose Utilization, Chengdu 610059, China.
authors: Dong Ge
authors: DG
authors: Tong