Photothermocatalytic CO₂ Reduction on Magnesium Oxide‐Cluster‐Modified Ni Nanoparticles with High Fuel Production Rate, Large Light‐to‐Fuel Efficiency and Excellent Durability

Abstract

Highly efficient CO2 reduction to produce fuel driven by solar energy is of great significance to alleviate the greenhouse effect and realize solar energy storage. Herein, a unique nanocomposite of MgO‐cluster‐modified Ni nanoparticles supported on Ni‐doped MgO (MCM–Ni/Ni–MgO) is synthetized by a simple approach. Very high fuel production rate for H2 and CO (78.01 and 88.44 mmol min−1 g−1) as well as a large light‐to‐fuel efficiency (31.7%) are achieved by photothermocatalytic CO2 reduction by CH4 on MCM–Ni/Ni–MgO merely using focused UV–vis–IR illumination. This arises from efficient light‐driven thermocatalysis that is further enhanced by a photoactivation due to the activation energy being considerably reduced upon the illumination. More importantly, it exhibits excellent photothermocatalytic durability due to its extremely low carbon deposition rate of 8.85 × 10−4 gc h−1 g−1 catalyst, reduced by 39.2 times as compared with that of a reference sample of Ni nanoparticles supported on Ni‐doped MgO (Ni/Ni–MgO). The experimental evidences and the functional theory calculations reveal that the surface modification of Ni nanoparticles by MgO cluster not only inhibits the carbon deposition side reactions of CO disproportionation and CH4 complete dissociation, but also significantly accelerates the oxidation of carbon species, thus tremendously decreasing carbon deposition rate.

A Novel Synergetic Effect Between Ru and CeO2 Nanoparticles Leads to Highly Efficient Photothermocatalytic CO2 Reduction by CH4 with Excellent Coking Resistance

“…In accordance with the weight loss, we calculated the coke formation rate ( r C ) of Ru/CeO 2 during the 40 h of photothermocatalytic stability experiment. Ru/CeO 2 shows an extremely low r C of 5.26 × 10 −5 g C g −1 catalyst h −1 (Figure 6C), which is much lower than that of nonprecious metal (e.g., Ni, Co) [ 35–38,41,42 ] catalysts and precious metal catalysts (e.g., Ru) [ 39 ] for photothermocatalytic CRM. No carbon nanofibers were detected in the used Ru/CeO 2 through TEM characterization (Figure S2A, Supporting Information), which is in keeping with the result of TG‐MS.…”

“…Recently, the strategies of photothermocatalytic CO 2 reduction by H 2 O, [ 22–26 ] H 2 , [ 27–30 ] and CH 4 [ 31–42 ] have been developed. They have attracted more and more interest as they could integrate the advantages of both thermocatalytic CO 2 reduction (high catalytic efficiency) [ 43,44 ] and photocatalytic CO 2 reduction (light‐to‐fuel conversion), and fully utilize solar energy including UV, visible, and infrared energy.…”

“…[ 22–30 ] Among the strategies, photothermocatalytic CO 2 reduction by CH 4 to produce CO and H 2 (CRM, CO 2 + CH 4 = 2CO + 2H 2 , Δ H 298 = 247 kJ mol −1 ) by using nanostructured group VIII metal nanoparticles as catalysts is especially attractive, as it could not only convert the two greenhouse gases to fuels but also simultaneously achieve high r fuel and η . [ 35–42 ] For the photothermocatalytic CRM strategy, there are two key challenges to be addressed. One is to continuously improve r fuel and η .…”

“…Extensive efforts have been devoted to tackling the challenges by designing various efficient photocatalysts which could utilize visible, even infrared, energy in sunlight. Recently, the strategies of photothermocatalytic CO 2 reduction by H 2 O, [22][23][24][25][26] H 2 , [27][28][29][30] and CH 4 [31][32][33][34][35][36][37][38][39][40][41][42] have been developed. They have attracted more and more interest as they could integrate the advantages of both thermocatalytic CO 2 reduction (high catalytic efficiency) [43,44] and photocatalytic CO 2 reduction (light-to-fuel conversion), and fully utilize solar energy including UV, visible, and infrared energy.…”

High Fuel Yields, Solar‐to‐Fuel Efficiency, and Excellent Durability Achieved for Confined NiCo Alloy Nanoparticles Using MgO Overlayers for Photothermocatalytic CO2 Reduction

“…In addition, MgO practically possesses identical lattice parameters with NiO, which can increase the dispersion of Ni particles by forming a solid solution with NiO. [37,39] However, there are no reports on the effect of NiCo alloy nanoparticles confined using MgO overlayers on photothermocatalytic CRM performance. DOI: 10.1002/solr.202200369 Solar-energy-driven CO 2 reduction to produce fuel is of great importance for alleviating the greenhouse effect and energy shortage.…”