Methanation of Carbon Dioxide over Ni–Ce–Zr Oxides Prepared by One-Pot Hydrolysis of Metal Nitrates with Ammonium Carbonate

Wangxin Nie,Weizhong Ding,Chenju Chen,Xiujing Zou,Xionggang Lu,Xueguang Wang

doi:10.3390/catal7040104

Abstract

Ni–Ce–Zr mixed oxides were prepared through one-pot hydrolysis of mixed metal nitrates with ammonium carbonate for CO2 methanation. The effects of Ce/Zr molar ratio and Ni content on catalysts’ physical and chemical properties, reduction degree of Ni2+, and catalytic properties were systematically investigated. The results showed that Zr could lower metallic Ni particle sizes and alter interaction between Ni and supports, resulting in enhancements in the catalytic activity for CO2 methanation. The Ni–Ce–Zr catalyst containing 40 wt % Ni and Ce/Zr molar ratio of 9:1 exhibited the optimal catalytic properties, with 96.2% CO2 conversion and almost 100% CH4 selectivity at a low temperature of 275 °C. During the tested period of 500 h, CO2 conversion and CH4 selectivity over Ni–Ce–Zr catalyst kept constant under 300 °C.

Highlights

The increasing emissions of CO2 have caused global warming and climate change, affecting human life and the ecological environment, due to the ‘greenhouse effect’
Among the viable solutions to mitigate CO2 emissions, many studies focused on two strategies: (i) CO2 capture and sequestration; and (ii) CO2 conversion to biofuels and high-value chemicals [1,2,3]
Ni–Ce–Zr mixed oxides were prepared through one-pot hydrolysis of mixed metal nitrates with ammonium carbonate

Summary

Introduction

The increasing emissions of CO2 have caused global warming and climate change, affecting human life and the ecological environment, due to the ‘greenhouse effect’. CO2 fixation has attracted much interest in achieving a low carbon economy and society. Among the viable solutions to mitigate CO2 emissions, many studies focused on two strategies: (i) CO2 capture and sequestration; and (ii) CO2 conversion to biofuels and high-value chemicals [1,2,3]. With regards to upcoming energy challenges, CO2 conversion seems to be a more attractive and promising approach [2,3]. Considering that the consumption of fuels is two orders of magnitude higher than that of chemicals, CO2 has to be mainly converted into energy carriers such as methane, methanol, and so on [4,5,6,7,8,9].

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Results

Conclusion