High value utilization of waste blast furnace slag: New Ni-CeO2/hBFS catalyst for low temperature CO2 methanation

In the steel industry, large amounts of blast furnace slag (BFS) by-products are inevitably produced and a lot of carbon dioxide is emitted. But at present, slag reuse technology has low added value. In this paper, a high value-added process using blast furnace slag to prepare catalysts for the hydrogenation of carbon dioxide to methane was proposed. Ni-CeO2/hBFS catalyst was prepared by primary wet impregnation using nitric acid modified blast furnace slag (BFS) as a support. CO2 conversion of Ni-CeO2/hBFS catalysts achieved 81.6 % at 350 °C, and the catalyst was not significantly deactivated in a 100 h stability test. The results indicate that: the addition of CeO2 improved the dispersion of Ni particles at high loadings, limited the growth of the Ni particle size and enhanced the synergy between the CO2 adsorption sites, the catalytic active sites and the support, thus improved the catalytic performance at low temperatures. This study provides an effective way for carbon dioxide emission reduction and high-value utilization of blast furnace slag, and developed a Ni-CeO2/hBFS catalyst with superior stability and catalytic performance in long-term operation, thus, the catalyst has great potential for industrial application in the carbon dioxide methanation reaction.