Cu Atoms on Nanowire Pd/H_yWO_3–x Bronzes Enhance the Solar Reverse Water Gas Shift Reaction

Abstract

Nanowire hydrogen bronzes of WO 3 nanowires decorated with Pd (Pd/H y WO 3−x ) were previously demonstrated to effectively capture broadband radiation across the ultraviolet to near-infrared wavelength range and catalyze the reverse water gas shift reaction (RWGS). Herein, we report a synthetic strategy to enhance the performance of this class of photocatalysts by conformally coating Cu atoms onto the surface of Pd/ H y WO 3−x by anchoring Cu(I)O t Bu to the Brønsted acidic protons of the bronze. The resulting materials are characterized by a suite of analytical methods, including electron microscopy and X-ray absorption spectroscopy. In addition, in situ diffuse reflectance infrared Fourier transform spectroscopy demonstrated that for the lightdriven RWGS reaction, as little as 0.2 at. % Cu facilitates the formation of surface carboxylate species from CO 2 , resulting in a 300−500% enhancement in the rate of CO production. This metal anchoring method enables atom precise modification of the surfaces of metal oxide nanomaterials for catalytic applications, circumventing the need for complex and expensive atomic layer deposition processes.

A quasi-stable molybdenum sub-oxide with abundant oxygen vacancies that promotes CO2 hydrogenation to methanol

“…These catalytic cycles and the cooperative effect at the Pt-H x MoO 3Ày interface facilitate efficient CO 2 hydrogenation under relatively mild reaction conditions. 38,74,75 The proposed reaction mechanism is totally different from the one known for the conventional Cu-based catalysts which normally require much higher reaction temperatures. 39,45,46 In addition, recyclability of the Pt/H x MoO 3Ày (300) catalyst was investigated in recycling tests (Fig.…”

“…Aer the introduction of CO 2 , two distinct peaks were observed at 1404 and at around 1530 cm À1 , the former being commonly assigned to symmetric stretching vibration mode of monodentate carbonate species (n s (OCO À )) (major species) and the latter being characteristic of the C]O stretching vibration of bidentate carbonates (minor species). 23,[73][74][75] Aer the introduction of H 2 , a broad band assignable to gaseous CO was observed at around 2130 cm À1 , [74][75][76] indicating that the CO 2 adsorbed on the catalyst underwent deoxygenation to produce CO, although such a peak was not observed before H 2 introduction because of only a small yield of CO. Along with the increase in time, several additional features associated with the hydrogenated products were observed with increased IR intensity; the peaks observed at 2851 and 2922 cm À1 are assignable to stretching vibrations of C-H bond.…”

CO2 Footprint of Thermal Versus Photothermal CO2 Catalysis

“…[1] Chemical transformation of CO 2 into CO and CH 4 can help solve this problem. [2] Thermocatalysis, [3] electrocatalysis, [4] photocatalysis, [5] and, most recently, photothermal catalysis [6] have been demonstrated to be effective strategies to enable the reduction of CO 2 to value-added chemicals. Power used in these catalytic processes has often been provided by fossil-fuel-generated electricity.…”

High-Performance, Scalable, and Low-Cost Copper Hydroxyapatite for Photothermal CO2 Reduction

“…In recent years, the intensification of climate change and increasing demand for renewable chemicals and clean energy have triggered enormous research attention. − Among many possible solutions to these issues, the gas-phase photoreduction of CO 2 to CO via the reverse water gas shift (RWGS) reaction stands out, due in part to the ability of CO to serve as a feedstock in the production of both value-added chemicals and renewable fuels. − Unfortunately, the best-performing catalysts for this reaction often contain expensive or toxic elements. − Thus, the development of a catalyst with high performance, industrially relevant scalability, and competitive cost is a pivotal challenge for photocatalytic gas-phase hydrogenation of CO 2 . − ,− − ,− As a result, one of the greatest obstacles to the further development of this technology is the identification of a suitable catalyst material.…”