Plasmon-enhanced reverse water gas shift reaction over oxide supported Au catalysts

Abstract

We show that localized surface plasmon resonance (LSPR) can enhance the catalytic activities of different oxide-supported Au catalysts for the reverse water gas shift (RWGS) reaction. Oxide-supported Au catalysts showed 30 to 1300% higher activity for RWGS under visible light compared to dark conditions. Au/TiO 2 catalyst prepared by deposition-precipitation (DP) method with 3.5 nm average Au particle size showed the highest activity for the RWGS reaction. Visible light is converted into chemical energy for this reaction with up to a 5 % overall efficiency. A shift in the apparent activation energy (from 47 kJ/mol in dark to 35 kJ/mol in light) and apparent reaction order with respect to CO 2 (from 0.5 in dark to 1.0 in light) occurs due to the LSPR. Our kinetic results indicate that the LSPR increases the rate of either the hydroxyl hydrogenation or carboxyl decomposition more than any other steps in the reaction network.

Product selectivity in plasmonic photocatalysis for carbon dioxide hydrogenation

“…A high E ads,O partially compensates the energy cost for C–O bond cleavage in the CHO intermediates and increases the selectivity towards CH 4 . Although the reaction on the Au catalysts has been reported to involve additional reaction intermediates225960, the selectivity observed here is consistent with the corresponding E ads,O of Rh (5.22 eV) and Au (3.25 eV)61: the Rh catalyst had a slight preference towards CH 4 production under dark conditions, whereas the Au catalyst exclusively produced CO.…”

Heterojunction Synergies in Titania‐Supported Gold Photocatalysts: Implications for Solar Hydrogen Production

“…[22] The authors proposed that plasmonic near-fields coupled to optical transitions, which involvel ocalised electronic states in TiO 2 ,r esulted in enhanced visible-light absorption and electron-hole pair formation, whichi mpactedp hotocatalytic H 2 production directly.O ther studies also suggest that "hot" electrons are transferred from Au into the TiO 2 conduction band. [20,21,[48][49][50] The XRD patterns for the Au/TiO 2 photocatalysts ( Figure 2F) confirmed the presence of face-centred cubic (fcc) Au nanoparticles by the appearance of weak signals at 2 q = 38.2, 44.4, 65.6, 77.6 and 81.78 ( Figure S4). [51] XRD measurements also verified that the size of the TiO 2 particles did not change after Au deposition.…”

“…It has becomeahot topic of research because of its ability to activate TiO 2 for H 2 production under visible light. [19][20][21][22][48][49][50] This new,s table way to induce visiblelight driven H 2 production relies on ac omplexi nterplay of electronic energy levels that direct charge transfera tt he Auoxide interface. Several studies have put forward experimental evidencet oe xplain the mechanism of H 2 production driven by Au SPR.…”

Reverse Water–Gas Shift on Interfacial Sites Formed by Deposition of Oxidized Molybdenum Moieties onto Gold Nanoparticles

“…[28][29][30][31][32][33][34][35][36][37] Rodriguez et al studied WGS over Au/TiO 2 (110), and on the basis of experiments and theoretical calculations they concluded that the metalsupport interface is critical for the activation of water and the formation of a carboxyl intermediate which further decomposes into CO 2 and H 2 . 29 Ribeiro and co-workers elucidated the effect of the interface on water activation and determined that the WGS reaction rate scales linearly with the number of under-coordinated Au atoms, estimated from physical models of Au clusters and particle size measurements.…”