Roles of nitrogen species on nitrogen-doped CNTs supported Cu-ZrO2 system for carbon dioxide hydrogenation to methanol

• DOI: 10.1016/j.cattod.2017.04.017
• Publication Date: 2017-04-25T09:15:16Z
• Authors: Yuhai Sun; Limin Chen; Yunfeng Bao; Guannan Wang; Yujun Zhang; Mingli Fu; Junliang Wu; Daiqi Ye
• Keywords: 01 natural sciences; 7. Clean energy; 0104 chemical sciences

Abstract Cu-ZrO 2 catalysts supported on nitrogen-doped CNTs were tested for CO 2 hydrogenation to methanol in a fixed-bed plug flow reactor. The characterization results indicate that the presence of pyridinic nitrogen increases the copper oxide dispersion, promotes their reduction, decreases the Cu particle size and enhances H 2 adsorption capability; the activated CO 2 adsorption predominantly controls CO 2 conversion. In addition, pyridinic nitrogen contributes to the strong adsorption of CO 2 , stimulating methanol formation, while pyrrolic nitrogen contributes to the medium adsorption of CO 2 , mainly boosting CO formation. Thus, pyridinic nitrogen dominant CNTs supported catalyst (CZ/CNT-N) possesses more active sites compared with the other three catalysts, leading to maximum methanol yield (8.64%) and space time yield (102.21 mg g −1 cat h −1 ); pyrrolic nitrogen dominant CNTs supported catalyst (CZ/CNT-NH 2 ) obtains more highly active structure, giving the highest intrinsic activity (TOF values).