Synergistic Effect of FeNi Bimetallic Clusters for the Catalytic of Hydrogen Dissociation and Desorption: A Density Functional Theory Study

Fei Wu,Hao Zhang,Haigang Li,Chen Cheng,Shunxin Fei

doi:10.37358/rc.21.3.8434

Abstract

Cognition to the metal-metal interactions is of vital importance for the catalytic process and would help exploring novel catalysts. In the present study, the model system of FexNiy (x + y = 6) bimetallic clusters was utilized to study how metal-metal interactions influence the catalytic performance. The formation energies of different FeNi clusters, the hydrogen chemisorption energies together with the maximum hydrogen capacity and the saturated hydrogen atoms desorption energies were calculated. Bimetallic clusters exhibit a superior performance than pure clusters. Especially, Fe2Ni4 cluster has the highest hydrogen loading capacity, the most facile hydrogen molecule dissociation activation energy barrier and the lowest hydrogen atom desorption energy, suggesting that it is easier to dissociate H2 and release the H atoms. As a consequence, by adjusting appropriate metal/metal ratios, it is possible to design bimetallic catalysts with excellent catalytic performance.

Highlights

Transition metals are widely used in catalytic hydrogenation and dehydrogenation applications for their highly efficient catalytic performance [1−4]
The purpose of this study is to understand how metal-metal interaction affect the catalytic performance of a bimetallic catalyst
The results suggest that the average formation energies of FexNiy bimetallic clusters rises with the number of Ni atom increases, and Fe1Ni5 has the highest average formation energy of 2.33 eV

Summary

Introduction

Transition metals are widely used in catalytic hydrogenation and dehydrogenation applications for their highly efficient catalytic performance [1−4]. Corma et al synthesized bimetallic nanoparticles of CoNi@C catalyst by one step hydrothermal treatment with glucose assisted, the result showed that the catalytic activity of the obtained bimetal are five times higher than the corresponding monometallic Co@C catalyst on the selective hydrogenation of nitroarenes to corresponding anilines [24] They found that H2 chemisorption dissociation is the rate controlling step in the whole process. Another study on the NiFe@Cu hydrogen evolution catalyst showed that bimetal has a high activity in the catalytic conversion and selectivity [25] Those studies have greatly promoted the development of morphology control of bimetallic nanoparticles, the theoretical study of the reaction mechanism is rare, and cluster level insight would further promote the catalytic performance, especially in the atomic catalysis

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Conclusion