Constructing a Channel to Regulate the Electron-Transfer Behavior of CO Adsorption and Light-Driven CO Reduction by H₂ over CuO–ZnO

Abstract

Photocatalytic conversions of C1 molecules under mild conditions have been widely researched in many fields. Adsorption of reactants at a catalyst surface is an indispensable process for C1 conversion and thus it might play a key role in reaction behavior. Herein, for a ZnO sample without photocatalytic activity for CO + H2 reduction, CuO is introduced into ZnO to regulate the adsorption behavior of CO on the CuO–ZnO surface and then to drive the reduction of CO by H2 under UV irradiation. The results of gas sensitivity tests and various in situ characterization methods are as expected. Specifically, surface zinc vacancies and Cu2+ sites at the interface of ZnO and CuO cooperate to construct a special electron-transfer channel (Zn–O–Cu–O) for CO adsorption [CO (ads)]. A new linear adsorption mode of CO at Cu2+ sites occurs, and this successfully changes the electron-transfer behavior of CO (ads) from donating electrons (to ZnO) to accepting electrons (from CuO–ZnO) via electron-transfer channels and d-electrons of Cu2+ matching. Then, CO molecules are reduced by H2 under UV irradiation. The strategy here provides an insight into the design of highly effective catalysts as well as an in-depth understanding of the mechanism of C1 photocatalytic conversion.

Modification of In2O3 by electronic promoters to regulate electron transfer behavior of CO2/H2O adsorption and the selectivity of photocatalytic CO2 reduction

“…Most remarkably, the lattice-interlacing phenomenon (depicted in the yellow area in Fig. 7B) occurred between the InOF(131) plane and In 2 O 3 (222) plane, 31 indicating that F − grew in situ on the In 2 O 3 (222) surface during preparation, and F − was successfully incorporated into the lattice of In 2 O 3 , which was in agreement with the XRD results (Fig. 1A and B).…”

“…14), the broad bands in the range of 3700–2800 cm −1 were assigned to adsorbed H 2 O molecules. 31 Compared to the In 2 O 3 (B) sample, F–In 2 O 3 (B) had a stronger capacity to adsorb H 2 O due to its hydrophilic properties (the scale bar in Fig. 14B is far greater than that in Fig.…”

“…3A and C), this attenuates the effect of defects on the energy level of the samples, resulting in the increase in the Fermi level after modification with F − , which enhances the reducing ability of F–In 2 O 3 (B), and consequently, the HER was more likely to occur. 4,31 After modification with NH 2 + , a decrease in the Fermi level occurred due to the increase in V O concentration (Fig. 3B), which weakens the reducing ability of NH 2 –In 2 O 3 (B), and the HER was inhibited.…”

Lattice‐Strained Metallic Aerogels as Efficient and Anti‐Poisoning Electrocatalysts for Oxygen Reduction Reaction

“…In contrast to Pd@PdCo MAs/C, Pd MAs/C, and the commercial Pd/C, there is no CO adsorption peak in the CVs of Pd@PdBiCo MAs/C, indicating that Pd@PdBiCo MAs/C are inert to CO. Then, CO diffuses reflectance infrared Fourier transform spectroscopy (CO‐DRIFT) also confirmed the similar results with CO stripping (Figure 5a). The lack of significant CO adsorption characteristic peaks at 2173 and 2116 cm −1 for Pd@PdBiCo MAs reveals the excellent anti‐poisoning property [32,33] . Furthermore, the CH 3 OH diffuse reflectance infrared Fourier transform spectroscopy (CH 3 OH‐DRIFT) spectra of Pd@PdBiCo MAs, PdBiCo MAs, Pd@PdBi MAs, Pd@PdCo MAs, and Pd MAs are shown in Figure 5b.…”

“…The lack of significant CO adsorption characteristic peaks at 2173 and 2116 cm À 1 for Pd@PdBiCo MAs reveals the excellent anti-poisoning property. [32,33] Furthermore, the CH 3 OH diffuse reflectance infrared Fourier transform spectroscopy (CH 3 OH-DRIFT) spectra of Pd@PdBiCo MAs, PdBiCo MAs, Pd@PdBi MAs, Pd@PdCo MAs, and Pd MAs are shown in Figure 5b. CH 3 OH decomposition will produce *CH 3 and *OH, in which the stretching vibration peak of *CH 3 is around 1400 cm À 1 , and the stretching vibration peak of *OH is between 3000-3500 cm À 1 .…”