Photoinducing Different Mechanisms on a Co-Ni Bimetallic Alloy in Catalytic Dry Reforming of Methane

Abstract

Photothermal catalytic dry reforming of methane (DRM) is a promising process for simultaneous solar energy conversion and fossil fuel upgrading; however, its mechanistic difference from thermocatalysis has not been much investigated. Herein, we report a comprehensive mechanistic investigation of bimetal NiCo/SiO 2 in photothermo-and thermocatalytic DRM. Co substitution in Ni/SiO 2 poses a suppressing effect on thermocatalysis, while a promotion effect emerges after light irradiation. In situ diffuse reflectance infrared Fourier transform spectroscopy and theoretical simulations reveal that Co substitution thermodynamically inhibits the cleavage of C−H in methane, CO 2 dissociation, and CO desorption in thermal catalysis. While energetic hot carriers are evidenced in the NiCo alloy under light irradiation, they directly activate reactant molecules and overcome the thermodynamic barriers to selectively promote the generation of *CHO to CO instead of *C to coke. Thus, NiCo/SiO 2 achieves higher photo-to-thermal efficiency and prominent performance in photothermal catalytic DRM. This work unveils the intrinsic photo effects on non-noble bimetallic catalysts in photothermal catalytic DRM for developing robust photothermal DRM catalysts for practical applications.

Reinforcing the Efficiency of Photothermal Catalytic CO2 Methanation through Integration of Ru Nanoparticles with Photothermal MnCo2O4 Nanosheets

“…Recently conducted research has demonstrated that the incorporation of light irradiation into conventional thermal catalytic systems could significantly enhance CO 2 conversion efficiency under mild conditions, including various strategies of photothermal catalytic CO 2 reduction by H 2 , CH 4 , and H 2 O, establishing it as a rapidly advancing and captivating field of study. − Therefore, it is imperative to develop efficient catalysts for photothermal CO 2 conversion. So far, various heterogeneous catalytic systems have already been reported with supported plasmonic metal nanoparticle-based catalysts exhibiting promising potential. , Upon exposure to light irradiation, the localized surface plasmon resonance (LSPR)-induced hot electrons over metal nanoparticles directly injected into the antibonding orbitals of adsorbed molecules, facilitating the activation of adsorbed species and reducing energy barriers in key reaction steps. , In addition, the decay of electromagnetic fields produced around the metal/support interfaces arising from the LSPR effect would effectively elevate the local temperature of the catalyst, thereby promoting reaction kinetics. − Despite a lot of pioneering work on various plasmonic metal/semiconductor systems, such as Ru/H x MoO 3– y , Ir@UiO-66, and Co/La-TiO 2 , unfortunately, the unsatisfying light utilization capacity and limited catalytic behavior based on inert supports with relatively wide bandwidth still result in low efficiency for CO 2 conversion.…”

Challenges and opportunities for the photo-(thermal) synthesis of ammonia

“…Indeed, several recent studies have shown the hot carriers’ potential in mitigating the formation of unwanted byproducts, especially in the context of photo-thermal dry reforming of methane. 145,146…”

“…Indeed, several recent studies have shown the hot carriers' potential in mitigating the formation of unwanted byproducts, especially in the context of photo-thermal dry reforming of methane. 145,146 When it comes to thermal effects, the photo-induced heat at the nanoscale provides high temperatures at the active sites in a more efficient way compared to traditional thermo-catalysis. These elevated temperatures translate into catalytic activities that are several orders of magnitude above those obtained with conventional photo-catalysis, mainly due to both the improved reaction kinetics and energy-mass transfer.…”

Photothermal effect and application of photothermal materials in photocatalysis and photoelectric catalysis

“…Photothermal catalysis and organic degradation PC is a common method used in organic matter degradation, and the efficiency of photocatalytic pollution degradation can be further improved by using the photothermal effect [148,149] . Huang et al introduced oxygen vacancies into BiOI nanosheets (named BiOI-8) with low concentration nitric acids and applied them to photocatalytic degradation of formaldehyde [150] .…”