Low-coordinated surface atoms of CuPt alloy cocatalysts on TiO₂for enhanced photocatalytic conversion of CO₂

Abstract

We report the photocatalytic conversion of CO2 to CH4 using CuPt alloy nanoclusters anchored on TiO2. As the size of CuPt alloy nanoclusters decreases, the photocatalytic activity improves significantly. Small CuPt nanoclusters strongly bind CO2 intermediates and have a stronger interaction with the TiO2 support, which also contributes to an increased CH4 generation rate. The alloying and size effects prove to be the key to efficient CO2 reduction, highlighting a strategic platform for the design of photocatalysts for CO2 conversion.

Dual Cocatalysts in TiO2 Photocatalysis

“…According to the elementary composition, cocatalysts can be classified into: noble metals (e.g., Pt, Au, Ag, Pd, and Rh), non‐noble metals (e.g., Cu and Ni), metal oxides (e.g., NiO, CoO x , MnO x , IrO x , CuO x , and RuO 2 ), metal hydroxides (e.g., Ni(OH) 2 , Cu(OH) 2 , and Co(OH) 2 ), metal sulfides (e.g., MoS 2 , WS 2 , CuS, and NiS), metal phosphides (e.g., Co 2 P, Ni 2 P, and MoP), and carbonaceous materials (e.g., graphene, carbon quantum dots, carbon nanotube, and graphdiyne) …”

“…When a cocatalyst is deposited on the surface of TiO 2 , an intimate contact can be formed at the interface, which results in the construction of heterojunction, thus facilitating the separation and transfer of charge carriers. iii)Cocatalysts can provide additional active sites and catalyze photocatalytic reactions . For instance, noble metals not only serve as electron sinks, but also provide effective proton reductions sites, hence dramatically promoting proton reduction reactions. iv)Cocatalysts can enhance the light harvesting . Some noble metal nanoparticles (NPs) (i.e., Au and Ag) can strongly absorb visible light due to the surface plasmon resonance (SPR) effect .…”

Electrochemical CO2 Reduction on Bimetallic Surface Alloys: Enhanced Selectivity to CO for Co/Au(110) and to H2 for Sn/Au(110)

“…where I x is the Q-mass ion signal intensity of x, and y is the reaction electron number for the following electrochemical reactions (2)(3)(4):…”

“…Various ways for converting CO 2 , one of the greenhouse-effect molecules, into useful valuable chemical substances, such as thermochemical catalytic reactions [1,2] and photocatalytic reactions, [3,4] have been studied to attain a CO 2 zero-emission society. The electrochemical CO 2 reduction (ECR) is an effective way to convert CO 2 to carbon monoxide (CO), [5][6][7][8] formic acid (HCOOH), [9][10][11] alcohol, [12][13][14] and various hydrocarbons.…”

Supported Porous Nanomaterials as Efficient Heterogeneous Catalysts for CO2 Fixation Reactions

“…Density functional studies revealed that Ni NPs at the surface of 55atom bimetallic CuNi NPs in core-shell architectures strongly adsorb and activates the CO 2 molecule, [128] which in turn promptly react with electron-rich substrates to give the CO 2 inserted products.L ee and co-workersh ave shown that for the photocatalytic reduction of CO 2 ,s mall CuPt nanoclusters strongly bind CO 2 intermediates and have as tronger interaction with the TiO 2 support (Figure 4), which also contributes to an increased CH 4 generation rate. [129] Oxides of all these reactive metalsc an be dispersed on microporous or mesoporous supports to yield ar ichs pectrum of heterogeneousc atalysts and often their surface acidity/basicity play crucial role in the CO 2 fixation reactions. Bimetallic Ni-CoN Ps supported over mesoporouss ilica MCF-17 showed catalytic reduction of CO 2 to am ixture of CO (70 %), HCHO (20 %) and CH 3 OH (10 %) at 350 8C; in this system surface alloying due to the migration of Ni from the core to shell nanostructure could be responsible for this selectivity pattern.…”