Switchable Structure Promoted Leaching Free Atomically Dispersed Pt Catalyst for Low Carbon Biomass Polyol Oxidation

Abstract

Achieving efficient catalytic conversion over heterogeneous catalyst with excellent resistance against leaching is still a grand challenge for sustainable chemical synthesis in aqueous solution. Herein, we devised a leaching free atomically dispersed Pt1/hydroxyapatite (HAP) catalyst with unique switchable structure via a simple and green in-situ anchoring strategy. Gratifyingly, this robust Pt1/HAP catalyst exhibits remarkable catalytic selectivity and catalyst stability for the selective oxidation of C2-C4 bio-polyols (e.g., ethylene glycol, propanediol, glycerol and butanediol) to corresponding primary hydroxy acids. X-ray absorption spectroscopy, in-situ Fourier Transform infrared spectroscopy, density functional theory calculation and kinetics study elucidated that the switchable Pt-(O-P) linkages with strong electronic-withdrawing function of PO43− (Pt1-OPO43− active site) not only realize the activation of C-H bond, but also destabilize the transition state from adsorbed hydroxy acids toward the C-C cleavage, resulting in the sharply increased selectivity of hydroxy acids. Moreover, the strong PO43−-coordination effect, originating from the enhanced interaction between positively charged Pt1 and negatively charged OPO43−, provides electrostatic stabilization for the atomically dispersed Pt, ensuring the highly efficient catalysis of Pt1/HAP for over 160 hours without metal leaching. This finding opens up new opportunities for efficient upgrading of bio-polyols over atomically dispersed catalysts.

Controlled synthesis of Ru-single-atoms on ordered mesoporous phosphine polymers for microwave-assisted conversion of biomass-derived sugars to artificial sweeteners

“…26,27 The microenvironment engineering of active sites by adjusting the neighboring steric effect of the organic ligand in the POP determines the adsorption of substrates, where phosphine and phosphates as ligand are utilized to tailor the selectivity of metal nanoparticles. 15,[27][28][29] Hence, phosphine exerts a unique "ligand effect" to adjust the neighboring environment of active metals. Thus, it would be encouraging to utilize the chemoselectivity of phosphinebased supports for hydrogenating C 5 and C 6 sugars, which is however extremely rare in the literature.…”