In this research, in an attempt to make use of the kaolin resources in Vietnam, we present a synthetic process of zeolite A via hydrothermal from kaolinite, together with the modification process of zeolite A using different metallic cations. The characteristics of the prepared zeolite LTAs such as chemical composition and crystalline structure, as well as their catalytic activity in the methanation reaction of carbon dioxide (CO2) to methane (CH4) were extensively investigated. | Cite this paper Vietnam J. Chem. 2023 61 2 170-177 Research article DOI Preparation and modification of zeolite A from kaolin for catalytic methanation of carbon dioxide Do Cao Son1 2 Vo Thi Kieu Anh4 Nguyen Thi Thom4 Huynh Le Thanh Nguyen2 3 Le Viet Hai2 3 Co Thanh Thien2 3 Nguyen Thai Hoang2 3 Tran Dai Lam4 Pham Thi Nam4 Nguyen Thi Thu Trang1 4 1 Graduate University of Sciences and Technology Vietnam Academy of Science and Technology VAST 18 Hoang Quoc Viet road Cau Giay district 10000 Hanoi Viet Nam 2 University of Science 227 Nguyen Van Cu road district 5 70000 Ho Chi Minh City Viet Nam 3 Vietnam National University of Ho Chi Minh City Vo Truong Toan road Linh Trung district Thu Duc City 70000 Ho Chi Minh City Viet Nam 4 Institute of Tropical Technology Vietnam Academic of Science and Technology VAST 18 Hoang Quoc Viet road Cau Giay district 10000 Hanoi Viet Nam Submitted February 28 2022 Revised April 28 2022 Accepted May 24 2022 Abstract Different types of zeolite including Zeolite A are prepared from natural kaolin originated in Vietnam. Raw kaolin was collected from Phu Tho Vietnam underwent metakaolization at 650 C within 2 hours and alkalination with NaOH to synthesize various zeolitic samples. Various characterization techniques were performed including X- Ray Diffraction Fourier-transform infrared spectroscopy and Scanning Electron Microscopy. Different concentrations of NaOH were utilized to study the difference of the prepared zeolite. Nickel-doped zeolite A samples with different nickel loading were also prepared via ion exchange method and were employed as catalyst for the hydrogenation of carbon dioxide CO2 to obtain methane CH4 . The best catalytic activity of CO2 conversion and CH4 selectivity was achieved with 10 Ni ZM1 at 350 C 1 atm H2 CO2 ratio of 4 1 and gas hourly space velocity of 9 000 . This study demonstrates a promising pathway of modifying Vietnamese natural kaolin as a low-cost but an .
