Contents lists available at ScienceDirect Energy Conversion and Management journal homepage: www.elsevier.com/locate/enconman Green and sustainable methanol production from CO 2 over magnetized FeeCu/core–shell and infiltrate mesoporous silica-aluminosilicates Wasakon Umchoo a,b , Chuleehat Sriakkarin a,b , Waleeporn Donphai a,b, ⁎ , Chompunuch Warakulwit b , Yingyot Poo-arporn c , Pongsakorn Jantaratana d , Thongthai Witoon a,b , Metta Chareonpanich a,b, ⁎ a KU-Green Catalysts Group, Center of Excellence on Petrochemical and Materials Technology, Department of Chemical Engineering, Faculty of Engineering, Kasetsart University, Bangkok 10900, Thailand b NANOTEC Center for Nanoscale Materials Design for Green Nanotechnology and Center for Advanced Studies in Nanotechnology for Chemical, Food and Agricultural Industries, KU Institute for Advanced Studies, Kasetsart University, Bangkok 10900, Thailand c Synchrotron Light Research Institute, Nakhon Ratchasima 30000, Thailand d Department of Physics, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand ARTICLE INFO Keywords: FeeCu catalyst Mesoporous silica-aluminosilicate Core-shell structure Infiltrate structure CO 2 hydrogenation External magnetic field ABSTRACT In this present work, green and efficient utilization concepts in the form of the use of an external magnetic field have been applied to improve catalytic performance in CO 2 hydrogenation. The 10Fee10Cu catalysts with two types of supports, core–shell and infiltrate mesoporous silica-aluminosilicate materials, were applied under external magnetic fields of different intensities (0, 20.8 mT, 27.7 mT) and orientations (north-to-south (N–S), south-to-north (S–N) directions). It was found that a magnetic field considerably enhanced both CO 2 conversion and methanol and DME selectivities. The highest CO 2 conversion was obtained over 10Fee10Cu/infiltrate catalyst under the magnetic field conditions of 27.7 mT and 4N–S direction at 260 °C (conversion was 1.5 times greater than that without a magnetic field). Under such conditions and at 240 °C, the highest methanol and DME space time yields were obtained, with results 1.8–1.9 times higher than those of without a magnetic field. These excellent performances could be ascribed to the superior adsorption of CO 2 and H 2 reactant gas molecules over the surface of magnetized catalysts under external magnetic field. This leads to the advantages of the catalyzed CO 2 hydrogenation–decreases in the operating temperature and simultaneous reduction in CO 2 emission to the atmosphere. This therefore facilitates a carbon-neutral route of CO 2 utilization. 1. Introduction Over the past decades, increases in carbon dioxide (CO 2 ) emissions have directly affected climate change and global warming [1–3]. These large amounts of CO 2 come from human activities, combustion of coal and fossil fuels as energy sources for industries, electricity production, and transportation [1,2,4]. Indeed the carbon dioxide concentration in the atmosphere has consequently risen from ∼280 ppm before the in- dustrial revolution to ∼410 ppm in 2017, and is further predicted to reach ∼570 ppm by the end of the century [5,6]. Consequently, utili- zation of CO 2 to produce value-added chemicals, fuels, and alternative energy can potentially minimize and improve global warming and cli- mate change problems [2,4,7]. The development of emerging green technologies with environ- mental sustainability has become an important issue. Among other methods for CO 2 utilization, CO 2 hydrogenation reaction is one of the most effective ways to approach the environmentally friendly synthesis of sustainable chemicals and fuels [4,5,7,8]. It has been found that methanol, dimethyl ether (DME), and chemical feedstock can be pro- duced using a low reaction temperature and low pressure through this hydrogenation reaction [7–10]. The drawback due to low methanol and DME productions, the secondary reaction to carbon monoxide (CO) and methane (CH 4 ) was still significantly observed. In order to improve methanol and DME selectivities, an external magnetic field is of a great interest to be applied to a conventional reactor. An external magnetic field has been successfully applied in various processes especially a fluidized bed reactor––as a tool to control movement of magnetic particles, eliminate slugging and channeling, and reduce agglomeration of magnetic particles [11–13]. However, there is little available research regarding the direct effect of external https://doi.org/10.1016/j.enconman.2017.12.101 Received 26 October 2017; Received in revised form 20 December 2017; Accepted 31 December 2017 ⁎ Corresponding authors at: KU-Green Catalysts Group, Center of Excellence on Petrochemical and Materials Technology, Department of Chemical Engineering, Faculty of Engineering, Kasetsart University, Bangkok 10900, Thailand. E-mail addresses: fengwod@ku.ac.th (W. Donphai), fengmtc@ku.ac.th (M. Chareonpanich). Energy Conversion and Management 159 (2018) 342–352 0196-8904/ © 2018 Elsevier Ltd. All rights reserved. T