In this study, we successfully synthesized Zn-Sn and Al-Sn catalysts by the combination of co-precipitation and hydrothermal methods. These catalysts were prepared by hydrothermal method using ZnCl2, SnCl4 and AlCl3 precursors. Structure and physical properties of catalysts were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). | Vietnam Journal of Science and Technology 56 (3B) (2018) 235-243 SYNTHESIS OF SOLID ACID-BASE CATALYSTS BASED ON Zn-Sn AND Al-Sn USED FOR CARBONYLATION OF GLYCEROL WITH UREA INTO GLYCEROL CARBONATE Ba Khiem Nguyen1, 2, *, T-Que Phuong Phan3, Huu Thien Pham3, Dinh Thanh Nguyen2, 3 1 College of Construction No2, No 190 Vo Van Ngan, Binh Tho Ward, Thu Duc District, Ho Chi Minh City 2 Graduate University of Science and Technology, No 18 Hoang Quoc Viet Street, Nghia Do Ward , Cau Giay District, Ha Noi 3 Institute of Applied Materials Science - VAST, No 1A TL 29 Street, Thanh Loc Ward, District 12, Ho Chi Minh City * Email: nguyenbakhiem789@ Received: 24 July 2018; Accepted for publication: 8 September 2018 ABSTRACT In this study, we successfully synthesized Zn-Sn and Al-Sn catalysts by the combination of co-precipitation and hydrothermal methods. These catalysts were prepared by hydrothermal method using ZnCl2, SnCl4 and AlCl3 precursors. Structure and physical properties of catalysts were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). The products of glycerol conversion product was also tested by gas chromatography. The catalytic activity of Zn-Sn and Al-Sn depends on reaction conditions (temperature and catalysts). The main product formed after the carbonylation reaction was glycerol carbonate. The selectivity of the main product was highest when using the Zn-Sn catalyst 5 % at a 145 °C during 5 hours, that the yield was %, the conversion degree was % and the selectivity was %. For AlSn catalyst under the same reaction conditions, the efficiency was % and the product selectivity achieved up to %. Keywords: catalysts, co-precipitation method, glycerol, glycerol carbonate. 1. INTRODUCTION In biodiesel production, the amount of glycerol accounts for about 10% of the products, along with the demand for biodiesel, a large amount of glycerol is produced, but the value is relatively low. Thus .