Crystal Phase Sensitivity of 5-Hydroxymethylfurfural Hydrodeoxygenation over a Pt₁Co Single-Atom Alloy Catalyst

Abstract

In reactions of hydrodeoxygenation (HDO) of biomass-derived chemicals, one promising method for improving the yield of desirable products is to control the crystal phase of the catalyst and thus the adsorption configuration of intermediates. In this work, we have investigated the catalytic activity and selectivity of Pt 1 Co single-atom alloy (SAA) catalysts with fcc (face-centered cubic) and hcp (hexagonal close-packed) cobalt crystal phases toward 5-hydroxymethylfurfural (5-HMF) HDO reaction by density functional theory (DFT) calculation. Potential energy profiles of 5-HMF HDO reactions on the Pt 1 Co-fcc and Pt 1 Co-hcp surfaces show that the Pt 1 Co-hcp surface has a lower hydrogenation energy barrier (0.96 and 0.83 eV) and C−O bond cleavage energy barrier (0.58 and 0.44 eV) than the Pt 1 Co-fcc surface, indicating the Pt 1 Co-hcp surface exhibits higher catalytic activity. Ring-opening energy and ring hydrogenation calculations distinguish product selectivity: the optimal product on the Pt 1 Cohcp surface is 2,5-dimethyltetrahydrofuran (DHMF), but 2-hexanol on the Pt 1 Co-fcc surface, which is caused by atomic density difference from the crystalline phase. This work provides a new theoretical support to improve reaction activity and product selectivity by controlling the crystal phase of biomass HDO catalysts.

Single-Atom Metal Catalysts for Catalytic Chemical Conversion of Biomass to Chemicals and Fuels

“…In terms of non-noble metals, Lu et al prepared Co 1 @Mo/ NC with Co−N 4 sites by the coordinative pyrolysis method and subjected it to the HDO of HMF. The reaction offered a 77% DMF yield and a 28.7 h −1 TOF value under 2.0 MPa H 2 , 170 °C, and 8 h. 72 A synergistic effect between the Co and the Mo sites 74 The results showed that Pt 1 @ Co-hcp offered a higher catalytic performance than Pt 1 @Co-fcc in the production of DMTHF, originating from the different exposed crystal phases and atomic densities. It was demonstrated that the desirable product on the Pt 1 @Co-hcp surface was DMTHF, while that on the Pt 1 @Co-fcc surface was 2hexanol.…”

“…Controlling the adsorption configuration of HMF on the catalyst surface provides a viable route to enable a mild conversion. Shi et al calculated the effect of Pt 1 @Co SAA with different cobalt crystal phases (face-centered cubic (fcc) and hexagonal close-packed (hcp)) on the HDO of HMF . The results showed that Pt 1 @Co-hcp offered a higher catalytic performance than Pt 1 @Co-fcc in the production of DMTHF, originating from the different exposed crystal phases and atomic densities.…”

Selective hydrogenation of lignocellulosic biomass over single-atom catalysts

“…Recently, a DFT calculation analysis has revealed the crucial roles of the crystal phase of SACs on the reaction selectivity. 56 The optimal products were identified to be 2-hexanol and DHMF on Pt 1 Co-fcc (face-centered cubic) and Pt 1 Co-hcp (hexagonal tightly packed) catalysts, respectively. The crystal phase affects the adsorption configuration of the intermediates.…”

Advances in Selective Hydrogenation of 5-Hydroxymethylfurfural over Heterogeneous Metal Catalysts

“…Yawen Shi et al investigated the catalytic movement and separability Pt 1 Co-fcc and Pt 1 Co-hcp catalysts of Pt 1 Co single-atom composition metal (SAA) with fcc (face-centered cuboid) and hcp (hexagonal close-packed) cobalt crystalline stages for the HDO reaction of HMF, separately, by using density flooding theory (DFT) calculations. The best product on the Pt 1 Co hcp surface was DHMF, while the best product on the Pt 1 Co-fcc surface was 2-hexanol, comparing the reactivity and regioselectivity of the HDO reaction for HMF conversion on the Pt 1 Co-fcc and Pt 1 Co-hcp surfaces [33]. The work of Yawen Shi's team was successful in developing HDO catalysts with high performance by precise tuning of crystal phases.…”