Pd-Promoter/MCM-41: A Highly Effective Bifunctional Catalyst for Conversion of Carbon Dioxide

Abstract

As on today, the conversion of carbon dioxide into methanol has been considered as one of the top research priorities all over the world. In this work, a series of supported Pd catalysts was prepared by impregnation method with using Pd (NO 3 ) 2 as a precursor and employed as a catalyst in the synthesis of methanol from carbon dioxide. In this process, the surface area and pore volume of support affected the Pd dispersity and catalytic activity of supported Pd catalyst. At the same time, the catalytic performance was enhanced when the alkaline earth oxide CaO was used as a promoter, and the effect of the loading of Pd and promoter was investigated. The 12.1 % of CO 2 conversion and the 65.2 % of selectivity for methanol were obtained over the catalyst Pd 6 Ca 3 /MCM-41 at 9 h onstream. Graphical AbstractPd CaO 3H 2 CO 2

Free-standing graphene/bismuth vanadate monolith composite as a binder-free electrode for symmetrical supercapacitors

“…GR only exhibits a broad peak centered at 24.1 indicating the formation of a poorly ordered graphite-like material. 21 The XRD pattern of the as-prepared BiVO 4 powder gives a crystalline monoclinic phase with lattice constants a ¼ 0.5185 nm, b ¼ 1.1713 nm and c ¼ 0.5102 nm which are in good agreement with literature values (JCPDS card no. 014-0688).…”

Mechanistic Understanding of Alloy Effect and Water Promotion for Pd-Cu Bimetallic Catalysts in CO2 Hydrogenation to Methanol

“…Current efforts have focused on the development of highly active, selective, and stable catalysts for methanol synthesis from CO 2 hydrogenation. − Cu-based materials have been studied for CH 3 OH synthesis from CO 2 ; − however, the catalytic activity is structure-dependent and sensitive to the composition of Cu-based catalysts. Previous studies have shown that adding promoters such as K, La, and Ba can improve the adsorption strength of CO 2 , stabilize surface intermediates, and enhance CH 3 OH selectivity. − An appropriate support not only affects the formation and stabilization of the active phase of the catalyst but also is capable of modulating the interactions among the adsorbates, catalyst surface, and promoter. − A previous study by Yang and co-workers showed significant CH 3 OH promotion by the presence of a small amount of water in low-temperature conversion of CO/H 2 and CO 2 /H 2 mixtures to methanol over Cu catalysts . Zhao et al performed DFT calculations to investigate the reaction network and effect of water on CO 2 hydrogenation to methanol on Cu(111); they found a significant decrease in the kinetic barrier for carboxyl (−COOH) formation from CO 2 hydrogenation via a unique hydrogen transfer process with involvement of H 2 O, which leads to a favorable reaction pathway for CH 3 OH production via a −COOH species rather than through a formate (−HCOO) intermediate …”

A review of plasma-assisted catalytic conversion of gaseous carbon dioxide and methane into value-added platform chemicals and fuels

“…43,49,50 In addition, several detailed studies were devoted to the inuence of Ga and Pd and it was found that the catalytic performance of the Cu/Zn-based catalyst was improved when even little amounts of Ga and Pd were added. 51,52 Nevertheless, the high cost of these additives hindered their practical application. However, the CH 3 OH yield in most experiments is typically below 30%.…”