*Corresponding author, e-mail: filizb@gazi.edu.tr Research / Review Article GU J Sci33(x): x-x (2020) DOI: Gazi University Journal of Science http://dergipark.gov.tr/gujs CO Methanation Over SAPO-34 Supported Ni Catalysts Yusuf Serkan KILINÇ 1,* , Filiz BALIKÇI DEREKAYA 2 1 Gazi University, Graduate School Of Natural And Applied Sciences, Advanced Technologies Department, 06500, Ankara, Turkey 2 Gazi University, Faculty of Engineering, Chemical Engineering Department, 06570, Ankara, Turkey Highlights • The effect of the preparation method on NiO/SAPO 34 catalysts was determined. • Changing the solvent changed both physical and activity properties. • The surfactant changed both physical and catalytic properties. Article Info Abstract This study investigated carbon monoxide methanation with 15 %NiO doped SAPO-34 zeolite- supported catalysts. The SAPO-34 support was produced by hydrothermal synthesis, and nickel oxide was added to the support by impregnation and surfactant-assisted impregnation method, dissolved in different solvents (water, ethanol, acetone, and 1-propanol). Various characterization techniques, N 2 physisorption, XRD, SEM, TEM, and FTIR, were used to determine the physical properties of catalysts. XRD analysis showed that synthesizing the catalysts with surfactant reduced the crystallite size. The average crystal sizes of the catalysts synthesized using the impregnation and surfactant-assisted impregnation methods are between 11.3-7.1 nm and 8.9-7.1 nm, respectively. The N 2 physisorption analysis showed that the catalysts with the surfactant assisted impregnation method had higher surface areas among the catalysts produced by the two different preparation methods. It was observed that the surface area of the catalyst increased as the boiling point of the solvent increased. Scanning electron microscopy (SEM) analysis exhibited that the particle size of the catalysts with 1-propanol prepared by impregnation and surfactant-assisted impregnation methods are 118 nm and 86 nm, respectively. According to the results, surfactants cause to produce smaller particles. The CO methanation studies showed that the highest CO conversion values were reached with Ni/SAPO-34 catalyst using 1- propanol prepared by impregnation and other method, which gave 19.2% and 21.1% CO conversion to methane at 375C, respectively. The low methane formation rates showed that most of the CO component was adsorbed on the surface, and some were converted to methane. . Received: 03 Jun 2022 Accepted: 01 Oct 2022 Keywords Methanation Carbonmonoxide SAPO-34 Surfactant Zeolite 1. INTRODUCTION The polluting effects of CO and CO 2 gases on the atmosphere are well-known phenomena. By reacting these gases with H 2 , it has become possible both to obtain an alternative fuel production and eliminate the harmful effects of these gases. Methanation reactions are frequently used to purify hydrogen in refineries and remove carbon oxides from gas mixtures in hydrogen or ammonia plants [1]. The choice of metal to be used as active component in catalytic reactions is important. Commonly used metals for methanation reaction include ruthenium (Ru), rhodium (Rh), iron (Fe), nickel (Ni), and cobalt (Co). Catalysts include such as Ru and Rh have the highest catalytic activity. However, their costs are quite high [2]. On the other hand, Fe has given low performance compared to other metals of selectivity despite its high activity [2]. Ni, frequently used among the catalysts, stands out with its high activity, selectivity and thermal stability. Although the performance of commonly used cobalt in catalytic reactions is close to Ni catalyst, it is more expensive than Ni [2]. In recent years, promising results have been revealed in the methanation studies in zeolite supports. In many studies, zeolites can be classified as synthetic and natural zeolites [3].