Selective Hydrogenation of CO₂ to Ethanol over Sodium-Modified Rhodium Nanoparticles Embedded in Zeolite Silicalite-1

Abstract

Catalytic transformation of CO 2 into chemicals in large demand such as ethanol has attracted much research attention under the background of establishing carbon-neutral societies. Supported Rh catalysts are promising candidates for the hydrogenation of CO 2 to ethanol but suffer from low ethanol productivity and poor catalyst stability. Here, we report that zeolite silicalite-1 embedded Na-promoted Rh nanoparticles (Na-Rh@S-1) demonstrate high productivity and stability for CO 2 hydrogenation to ethanol. The ethanol selectivity of 24% was attained at a CO 2 conversion of 10%, and the space-time yield of ethanol reached 72 mmol g Rh −1 h −1 , which outperformed most of the Rh-based catalysts reported to date. While a reference catalyst prepared by impregnation underwent deactivation, the Na-Rh@S-1 catalyst was stable for at least for 100 h owing to the confinement effect. The Na + modifier played crucial roles in enhancing the CO 2 conversion and ethanol selectivity by suppressing methane formation. The characterizations suggest that the presence of Na + enables the coexistence of Rh 0 and Rh + and enhances CO 2 adsorption, thus boosting ethanol formation. A comparative study between CO and CO 2 hydrogenation reveals that the Na-Rh@S-1 catalyst is significantly more active and selective toward CO 2 hydrogenation to ethanol.

Ti‐doped CeO2 Stabilized Single‐Atom Rhodium Catalyst for Selective and Stable CO2 Hydrogenation to Ethanol

“…It may be attributed to the enrichment of Ov sites and the increased supplying of H* species for enhancing CO formation on the Ov‐Rh Lewis‐acid‐base pairs, and these formed CO intermediate could not efficiently consume for its coupling with CH x * owing to the substantial difference in the structural and electronic properties between the Rh SAS and clusters. It is reported that metalic Rh sites favor the dissociation and hydrogenation of CO, while the Rh + sites are more favorable for the stabilization of CO [6c, 33] . According to our DFT calculation results, in spite of slightly more difficult for CO adsorption over Rh clusters, it shows much stronger ability of CO* hydrogenation to CH x O* intermediates for methanol formation (Figure S8).…”

Synthesis of methyl glycolate via low‐temperature hydrogenation of dimethyl oxalate over an efficient and stable Ru/activated carbon catalyst

“…1,19 Therefore, it is necessary to develop a high-efficiency catalyst for DMO to MG at low temperatures. Some noble metals such as Rh, 26,27 Pd, 28 Ru [29][30][31][32][33][34] are usually used for the hydrogenation of carbonyl groups, among which Ru catalyst shows excellent performance on low-temperature hydrogenation. Tan et al 30 reported that an efficient Ru/graphene catalyst could catalyze levulinic acid to γ-valerolactone at temperature as low as 0 °C.…”

“…Therefore, it is necessary to develop a high‐efficiency catalyst for DMO to MG at low temperatures. Some noble metals such as Rh, 26,27 Pd, 28 Ru 29‐34 are usually used for the hydrogenation of carbonyl groups, among which Ru catalyst shows excellent performance on low‐temperature hydrogenation. Tan et al 30 .…”

Boosting the Production of Higher Alcohols from CO2 and H2 over Mn- and K-Modified Iron Carbide

“…It is an effective and practical solution to convert CO 2 with H 2 from renewable energy sources to value-added products, such as methanol, lower olefins, and liquid fuels. − However, it is still challenging for the higher alcohol synthesis (HAS), which has wide application in industry. A rational design of catalysts is required to facilitate both the carbon chain growth and the insertion of oxygen-containing intermediates (like CO and CHO*) into the carbon chain. − …”