The influence of Mn, Zr and Pb promoters on the performance of Cu/ZnO/SBA-15 Catalyst for Hydrogenation of CO 2 to methanol Sara Faiz Hanna Tasfy 1,a , Noor Asmawati Mohd Zabidi 2,b , Maizatul Shima Shaharun 2,c , Duvvuri Subbarao 1,d 1 Department of Chemical Engineering, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, 31750 Tronoh, Perak, Malaysia. 2 Department of Fundamental and Applied Science, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, 31750 Tronoh, Perak, Malaysia. a miss25208@gmail.com, b noorasmawati_mzabidi@petronas.com.my, c maizats@petronas.com.my, d duvvuri_subbarao@petronas.com.my Keywords: CO 2 hydrogenation, methanol synthesis, promoter Abstract. The present work investigates the hydrogenation of CO 2 to methanol via a promoted Cu/ZnO/SBA-15 catalyst. In order to understand the effect of Mn, Zr and Pb promoters on the catalytic activity of Cu/Zn/SBA-15 catalysts, the hydrogenation of CO 2 was performed in a stirred high-pressure reactor at 483K, 22.5bar, and a H 2 /CO 2 ration of 3. The physicochemical properties of the catalysts were studied using N 2 physical adsorption, TEM and H 2 -TPR. The characteristics of catalysts depended on the type of promoter and it influenced their catalytic performance. The Mn and Zr promoters resulted in a larger surface area of the catalyst and improved catalytic activity and methanol selectivity. However, an opposite effect was found for the Pb promoter. A 10% improvement on the CO 2 conversion and 20% on the methanol selectivity was achieved due to the double promotion effect of Mn and Zr on Cu/ZnO-SBA-15 catalyst. Introduction The rising concerns about global warming and imbalance in the carbon cycle urge for a rapid development of an efficient CO 2 conversion process [1, 2]. The greenhouse effect is regarded as a serious threat to the global environment [3, 4]. The mitigation of carbon dioxide, a major greenhouse gas is an urgent issue. As a countermeasure, through catalytic hydrogenation of CO 2 a significant amount of CO 2 can be effectively converted into valuable products, such as methanol, which is a starting material for several chemicals, a medium for the storage and transportation of hydrogen and alternative energy source as well. The current commercial process is based on a Cu/ZnO/Al 2 O 3 catalyst which was introduced by ICI in 1966. Cu/ZnO/Al 2 O 3 catalysts have long been used in industrial methanol synthesis because of their high catalytic activity, long life time, high poison resistance, and relatively low reaction temperature and pressure [5]. Nevertheless, finding a better catalyst for methanol synthesis is still a subject of intense investigations. One of the methods to enhance the catalytic activity is by using promoters. Promotion of a heterogeneous catalyst (adding small amounts of one or more extra elements to a proven catalytic system) can have a huge impact on the catalytic properties. Promoters have been used to facilitate the reduction of the catalyst in addition to the adsorption and dissociation of the reactant which consequently affects the activity and selectivity of the product. The majority of the catalysts for CO 2 hydrogenation contained Cu and Zn as the main components together with different modifiers (Zr, Ga, Si, Al, B, Cr, Ce, V, Ti, etc.) [6, 7]. Xu et al. [8] studied the structure and catalytic performance of CuMnZrO 2 modified with Fe. They found that the presence of iron led to a decrease of the copper–zirconia interactions and reduced the methanol synthesis activity. Meshkini, et al. [9] investigated the effect of the metal oxide additives (Mn, Mg, Zr, Cr, Ba, W, and Ce) on the Cu/ZnO/Al 2 O 3 catalytic properties using a design of experiment approach (1/16 full factorial design) and they found that the addition of oxide metals influenced the catalytic activity, dispersion of Cu, Cu crystallite size, surface composition of catalyst and stability Defect and Diffusion Forum Vol 365 (2015) pp 178-182 © (2015) Trans Tech Publications, Switzerland doi:10.4028/www.scientific.net/DDF.365.178 All rights reserved. No part of contents of this paper may be reproduced or transmitted in any form or by any means without the written permission of Trans Tech Publications, www.ttp.net. (ID: 203.135.191.3-25/05/15,03:18:24)