Capsule‐Structured Copper–Zinc Catalyst for Highly Efficient Hydrogenation of Carbon Dioxide to Methanol. Issue 22 (22nd October 2019)

• Record Type: Journal Article
• Authors: Guo, Yongle; Guo, Xinwen; Song, Chunshan; Han, Xinghua; Liu, Hongyang; Zhao, Zhongkui
• Is Part Of: ChemSusChem. Volume 12:Issue 22(2019)
• Page Start: 4916
• Page End: 4926
• Publication Date: 2019-10-22
• Subjects: carbon dioxide -- hydrogenation -- core–shell structure -- heterogeneous catalysis -- methanol synthesis; Green chemistry -- Periodicals; Sustainable engineering -- Periodicals; Chemistry -- Periodicals; Chemical engineering -- Periodicals; 660
• DOI: 10.1002/cssc.201902485
• Languages: English
• ISSNs: 1864-5631

Abstract

Abstract: To develop a new and efficient CO2 ‐to‐methanol catalyst is of extreme significance but still remains a challenge. Herein, an innovative indirect two‐step strategy is reported to synthesize a highly efficient capsule‐structured copper‐based CO2 ‐to‐methanol catalyst (CZA‐r@CZM). It consists of a structurally reconstructed millimeter‐sized Cu/ZnO/Al2 O3 core (CZA‐r) with intensified Cu–ZnO interactions, which is made by a facile hydrothermal treatment in an alkaline aqueous solution, and a Cu/ZnO/MgO (CZM) shell prepared by an ethylene glycol‐assisted physical coating method. The CZA‐r core displays 2.7 times higher CO2 hydrogenation activity with 2.0 times higher CO selectivity than the previously reported Cu/ZnO/Al2 O3 (CZA‐p), whereas the CZM shell can efficiently catalyze hydrogenation of the as‐formed CO from the CZA‐r core to methanol as it passes through the shell. As a result, the developed capsule‐structured CZA‐r@CZM catalyst exhibits 2.4 times higher CO2 conversion with 1.8 times higher turnover frequency and 2.3‐fold higher methanol space–time yield than the CZA‐p catalyst (729.8 vs. 312.6 gMeOH kgcat −1 h −1 ). In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTs) experiments reveal that the CO2 hydrogenation reaction proceeds through a reverse water–gas shift reaction followed by a CO hydrogenation pathway via an *H3 CO intermediate. This work not only produces an efficient CO2 ‐to‐methanol catalyst, but also opens a new avenue for designing superior catalysts for other consecutive transformations. Abstract : Capsule Corporation : A capsule‐structured copper–zinc catalyst composed of a microstructure reconstructed millimeter‐sized Cu/ZnO/Al2 O3 core (CZA‐r) and Cu/ZnO/MgO shell (CZM) is prepared and employed in the CO2 ‐to‐methanol conversion, exhibiting 2.4 times higher CO2 conversion with 2.3‐folds higher methanol space–time yield (729.8 vs. 312.6 gMeOH kgcat −1 h −1 ) than the conventional Cu/ZnO/Al2 O3 catalyst.