Engineering Bimetallic Ni-Cu Nanoparticles Confined in MOF-Derived Nanocomposite for Efficient Dry Reforming of Methane

Zichen Du1

Fan Chen2

Siyuan Fang3

Xiaokun Yang4

Yulu Ge4

Kobi Shurtz1

Hong-Cai Zhou2

Yun Hang Hu3

Ying Li1,Email

1J. Mike Walker ‘66 Department of Mechanical Engineering, Texas A&M University, College Station, Texas, 77843, United States.
2Department of Chemistry, Texas A&M University, College Station, Texas, 77843, United States.
3Department of Materials Science and Engineering, Michigan Technological University, Houghton, Michigan 49931, United States.
4Chemistry Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States.

Abstract

To harness the potential of two significant greenhouse gases, CO2 and CH4, the dry reforming of methane (DRM) shows promise while the generation of syngas (CO and H2). Ni-based catalysts have shown promising catalytic activities, but they experience significant deactivation due to coke deposition and metal aggregation. In this study, we employed a metal-organic framework (MOF)-templated synthesis of novel structured catalysts, i.e. bimetallic Ni-Cu nanoparticles confined in MOF-derived carbon/ZrO2 nanocomposite (NiCu/C/ZrO2(MD)). Alloying a small amount of Cu with Ni reduced the overall metal particle size, enhanced CO2 adsorption and conversion, and facilitated NiO reducibility to Ni. In addition, the catalyst offered nanoconfinement of Ni-Cu NPs by the MOF-derived C/tegragonal-ZrO2 framework, which provided a large surface area, featured strong metal-support interaction, and hindered the detrimental filamentous carbon deposition and metal aggregation during DRM process. As a result, the 9Ni1Cu/C/ZrO2(MD) catalyst with a Ni/Cu weight ratio of 9:1 delivered high and stable DRM activities over 100-h DRM, with average CO2 and CH4 conversions at 76% and 77%, respectively, and H2/CO molar ratio at 1.07. This DRM performance is among the top ones reported in the literature, and it is much higher than that of a ZrO2-supported bimetallic Ni-Cu catalyst prepared by direct calcination with the same Ni/Cu weight ratio, 9Ni1Cu/ZrO2(DC). This work demonstrates the importance of two advanced DRM catalyst structures, bimetallic NiCu alloying and nanoconfinement in porous catalytic carbon/ZrO2 support, the combination of which significantly promoted carbon management and enhanced DRM activities.  

Engineering Bimetallic Ni-Cu Nanoparticles Confined in MOF-Derived Nanocomposite for Efficient Dry Reforming of Methane