Revealing the Sudden Alternation in Pt@h‐BN Nanoreactors for Nearly 100% CO₂‐to‐CH₄ Photoreduction

Abstract

How to develop an efficient photocatalyst with high activity and high selectivity is the biggest challenge limiting the application of photocatalysis. A reasonable design of the nanoreactor model is an effective strategy. Herein, a series of Pt nanoparticles coated with hexagonal boron nitride (Pt@h-BN) nanoreactors highly dispersed on a photochemically inert carrier, Al 2 O 3 substrate, are synthesized. The results show that as the number of h-BN coating layers increases, the selectivity of photocatalysis is altered from nearly 100% CO 2 -to-CO to nearly 100% CO 2 -to-CH 4 , and the optimized space-time yield of CH 4 is up to 184.7 μmol g (Pt) −1 h −1 with three-layer coating. The in situ characterizations reveal the cleavage of the CO on Pt to be the rate determining step and the existence of the key intermediate CO 2 − species on the surface of Pt@h-BN facilitates CH 4 formation. Notably, combined with detailed simulation calculations, this work reveals that the confinement effect in Pt@h-BN attributes the electrons mobility behavior and alleviate the interaction of COPt. What is more, the change of the reaction site is the essence for the sudden alternation. This work will bring a new insight to the selective catalysis of noble metals in the gas-solid phase.

Stabilization of Cu+ via Strong Electronic Interaction for Selective and Stable CO2 Electroreduction

“…The overall morphology of the Cu 2 O−BN sample was investigated by SEM (Figure 1c) and TEM (Figure 1d). The images of an isolated Cu 2 O−BN particle (≈700 nm in diameter) reveal an octahedral structure of Cu 2 O decorated with h‐BN layers on the surface, as marked by the white dotted circles in Figure 1c, d. The high‐resolution TEM (HRTEM) images of Cu 2 O−BN in Figure 1e, f show that the Cu 2 O nanoparticles were decorated with amorphous h‐BN thin layers, with a lattice spacing of 0.251 nm for the Cu 2 O (111) planes [21] and 0.356 nm for the h‐BN (002) planes, [45] as compared with those of pure Cu 2 O (0.258 nm, Figure S3) and the h‐BN sheets (0.369 nm, Figure S1d). The slightly compressed fringe spacings suggest the existence of strong interactions between Cu 2 O and h‐BN.…”

Following the Kinetics of Undercover Catalysis with APXPS and the Role of Hydrogen as an Intercalation Promoter

“…In particular, we expect pulsing experiments to provide a better understanding of the limitations in catalyst reactivity induced by mass transport limitations. Ultimately, we hope that pulsing experiments will become a compelling method for tracking the underlying reason for the increased undercover activity reported below several 2D materials. ,,,, …”

“…The reactivity of the catalytic support can be enhanced due to the confinement of the adsorbates, which results in the modification of the relevant electronic states. This phenomenon has been studied for multiple reactions in a variety of systems ,,, such as graphene-covered nanoparticles, , covered polycrystalline surfaces, for solution-phase reactions, and under a variety of 2D materials other than graphene. − Moreover, with such novel model systems, one can obtain a fundamental atomic-scale understanding of confined chemistry, similar to the approach developed by Ertl for noncovered catalytic surfaces …”

“…Such understanding is in fact also highly relevant for confined catalytic systems in general, as such systems can suffer from mass transport limitations. While multiple groups have demonstrated lower activation energy for 2D covered surfaces, ,,,,− ,, studies specifically addressing mass transport limitations hardly exist in the literature.…”

Hexagonal Boron Nitride Meeting Metal: A New Opportunity and Territory in Heterogeneous Catalysis

“…This provides an opportunity to tailor reaction selectivity with metal@h-BN nanostructures, which has been discussed in other confined nanoreactors. 90 A typical case is the photocatalytic CO 2 reduction reaction, 94 in which a stunning effect on the selectivity happened when Pt was covered by h-BN overlayers (Pt@h-BN). The reaction path changed from 100% CO 2 -to-CO to 100% CO 2 -to-CH 4 , as listed by 3D histogram in Figure 6e, and no activity was lost with optimized 3-layer h-BN covering.…”