Kaolin-derived zeolite-A-supported catalysts for catalytic methanation of carbon dioxide

Abstract

Zeolites, a type of microporous hydrated aluminosilicate minerals, are a popular candidate in the field of catalysis due to their high thermal stability as well as their good absorption capability. In this study, Vietnamese kaolin was employed as an unexpensive and abundant substitute for the synthesis of zeolite A. Nickel as well as several metallic were also incorporated in zeolite via ion exchange method. Ten-percent Ni/zeolite catalyst was studied the carbon dioxide (CO₂) conversion to methane (CH₄) in a fixed-bed tubular reactor. We observed that the highest catalytic activity of 55.2% CO₂ conversion and 92.7% CH₄ selectivity was obtained at 350 °C, 1 atm, H₂:CO₂ ratio of 4:1, and gas hourly space velocity (GHSV) of 9000 mL g⁻¹ h⁻¹. These results show a promising pathway of modifying Vietnamese natural kaolin as an economical and efficient alternative material for the preparation of zeolite A together with its catalytic application.