CO2 hydrogenation: Selectivity control of CO versus CH4 achieved using Na doping over Ru/m-ZrO2 at low pressure

CO2 Hydrogenation: Na Doping Promotes CO and Hydrocarbon Formation over Ru/m-ZrO2 at Elevated Pressures in Gas Phase Media

“…Carbon monoxide is then blended with hydrogen and either fed to an FTS reactor [ 17 ], producing hydrocarbons that are further upgraded to produce premium diesel, jet fuels, lubricants, and waxes, or to a methanol synthesis reactor to produce gasoline through the MTG process [ 18 ]. In previous work [ 19 ], RWGS catalysts based on an alkali dopant, Na, and 1%Ru supported on monoclinic zirconia, were explored at a low pressure of 1 bar. In the current contribution, we examine the same catalyst compositions (albeit different batches) at a higher pressure of 20 bar.…”

“…The catalyst functions of metal (e.g., Ru, Pt), defect-laded support (e.g., ZrO 2 ), and alkali (e.g., Na) were outlined in our previous work [ 19 ] and are rooted in the research of water–gas shift catalysis for the production and purification of H 2 for fuel cell applications. The water–gas shift function (in the current context, run in reverse) is a synergy between the surfaces of metal nanoparticles and defect sites (e.g., O-vacancies or Type II bridging of the OH group at partially reduced Zr sites) on the surfaces of monoclinic zirconia [ 24 , 25 ].…”

“…However, in this work, we first explored whether lowering the H 2 :CO 2 ratio to 3:1 (i.e., the stoichiometric ratio for RWGS/Fischer–Tropsch) would increase the CO selectivity (and decrease the CH 4 selectivity). To shed light on the mechanism, the catalysts were characterized by in situ DRIFTS of the CO 2 hydrogenation reaction at a low pressure using these realistic H 2 :CO 2 ratios (3:1 and 4:1 rather than 15:1, as used previously [ 19 ]). To gain insight into the question of whether CO 2 hydrogenation occurs directly or via a CO intermediate, the catalysts were subjected to a temperature programmed reaction by preadsorbing a H 2 :CO 2 mixture at the preferred ratio of 3:1.…”

“…The most promising catalysts were further tested using a fixed bed reactor at 20 bar in gas-phase media. For the purpose of experimental control, unpromoted and sodium-promoted 1%Ru/m-zirconia catalysts were prepared using a similar method to that used in our prior investigation conducted at a low pressure [ 19 ]; the new batches were characterized by the Brunauer–Emmett–Teller (BET) method, TPR/TPR-MS, TPR-EXAFS/XANES, and TPD-MS of CO 2 . These experiments confirmed that the catalysts were similar to prior batches (see the Supplementary Information for these routine characterization studies).…”

Editorial: Heterogeneous catalysts for C1 molecules conversion

“…The key to C1 molecules conversion is to design robust catalysts. A series of conventional thermal catalysts have been constructed and reported for C1 molecules conversion to fuels and chemicals ( Jin Z. et al, 2020 ; Parastaev A. et al, 2022 ; Rabelo-Neto R. C. et al, 2022 ). For the sustainable development to produce energy especially hydrogen energy, ethanol, gasoline, and starch, more and more photo-, electro, plasma-, bio-catalysts have been designed for the green conversion of C1 molecules.…”