Enhanced CH₃OH selectivity in CO₂ hydrogenation using Cu-based catalysts generated via SOMC from Ga^III single-sites

Abstract

CuGax alloy nanoparticles supported on SiO2 can be obtained by surface organometallic chemistry. This catalyst is active and selective for the hydrogenation of CO2 to CH3OH, related to the formation of an optimal interface between Cu and GaIIIOx.

Silica-supported PdGa Nanoparticles: Metal Synergy for Highly Active and Selective CO2-to-CH3OH Hydrogenation

“…1c, SI S7). This observation contrasts with what is observed for Pd@SiO 2 , where 2 bands of similar intensity at 2094 cm -1 and 1967 cm -1 , attributed to terminal and bridging species, 16,29 and is consistent with the formation of a PdGa alloy, where the presence of bridging CO-species is suppressed through dilution of surface Pd species. 30 This disparity highlights the intrinsic difference in the interaction of the particles with CO, which can be explained by the dilution of surface Pd by Ga 0 centers.…”

“…12 Therefore, alternative metals, oxide promoters and supports have been investigated. 5 In this context, Pd-containing systems (Pd/MO x ) [13][14][15][16][17][18] show superior activities to these based on Cu in the hydrogenation of CO 2 to CH 3 OH when supported on reducible oxides (ZnO or Ga 2 O 3 ). However, Pd-based catalysts display low CH 3 OH selectivity (<60%, Scheme 1b) due to the competing Reverse Water Gas Shift (RWGS) reaction (eq.…”

Stepwise construction of silica-supported tantalum/iridium heteropolymetallic catalysts using surface organometallic chemistry

“…This strategy has only been explored in very rare instances [13][14][15][16][17][18] and is different from sequential co-grafting or co-impregnation methods in which both metal sites are orthogonally attached to the support, independently of one another, and are typically converted to supported alloys or nanoparticles after thermal treatment. [19][20][21][22][23][24][25][26][27][28][ [29][30][31][32] The purpose of this article is to compare both routes (A and B) in the case of a tantalum-iridium system. We demonstrate that, although homogeneously distributed heterometallic species are formed using both approaches, the nature of the obtained surface species, and therefore the catalytic performances of these materials, are affected by the chosen synthetic methodology.…”

CO2 Hydrogenation to Methanol with Ga‐ and Zn‐Doped Mesoporous Cu/SiO2 Catalysts Prepared by the Aerosol‐Assisted Sol‐Gel Process**

“…More recently, Copéret and co-workers prepared alloyed CuGa nanoparticles supported on SiO 2 using a surface organometallic chemistry technique. [21] They assigned the enhanced catalytic activity and selectivity towards methanol to an increased interfacial area between Ga 2 O 3 and Cu 0 , where methoxy intermediates are stabilized. While the precise mechanism of promotion continues to be debated, it should be kept in mind that the hydrogenation of CO 2 to methanol on Cu-based catalysts is strongly structure-sensitive.…”

“…Performing in situ diffuse reflectance infrared Fourier‐transform spectroscopy (DRIFTS) during CO 2 hydrogenation reaction at steady state, they observed no influence of the Ga presence on the oxidation state of Cu (mainly Cu 0 ) but an enhanced formation of formate adsorbates on Ga 2 O 3 species. More recently, Copéret and co‐workers prepared alloyed CuGa nanoparticles supported on SiO 2 using a surface organometallic chemistry technique [21] . They assigned the enhanced catalytic activity and selectivity towards methanol to an increased interfacial area between Ga 2 O 3 and Cu 0 , where methoxy intermediates are stabilized.…”