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H2-Driven NADH regeneration has long suffered from low selectivity when non-enzymatic, particularly heterogeneous catalysts, are used. In addition to the unselective nature of the catalysts, the typically unmeasured NAD+ conversion has inevitably hindered catalyst development. Here we report Sn-doped Pt/SiO2 catalysts for the selective regeneration of NADH and show that doping Pt/SiO2 with 10 at% Sn can deliver a selectivity of 90% (at full conversion) using H2. We propose that this is a result of Sn disturbing the Pt ensemble, altering the mode of NAD+ adsorption and directing the reduction to the 1,4-position of the nicotinamide ring. [ABSTRACT FROM AUTHOR]

H2-Driven NADH regeneration has long suffered from low selectivity when non-enzymatic, particularly heterogeneous catalysts, are used. In addition to the unselective nature of the catalysts, the typically unmeasured NAD+ conversion has inevitably hindered catalyst development. Here we report Sn-doped Pt/SiO2 catalysts for the selective regeneration of NADH and show that doping Pt/SiO2 with 10 at% Sn can deliver a selectivity of 90% (at full conversion) using H2. We propose that this is a result of Sn disturbing the Pt ensemble, altering the mode of NAD+ adsorption and directing the reduction to the 1,4-position of the nicotinamide ring. [ABSTRACT FROM AUTHOR]

NAD(P)H is a key cofactor widely used in biocatalytic reductive transformations, facilitating a wide range of industrially significant reactions which ultimately result in the consumption of the costly cofactor. To make NAD(P)H dependent biotransformations sustainable and economically feasible, different catalytic routes have been investigated to regenerate NAD(P)H. Here we report a comprehensive life cycle assessment (LCA) of these catalytic regeneration methods. Midpoint characterisation and normalisation show that the synthesis of the catalyst, specifically the use of noble metals and energy consumption, dominate the environmental impacts and have the greatest contribution to all considered impact categories. This comparative LCA highlights the need for future investigation into noble metal based catalyst alternatives, to provide cleaner and more sustainable methods of regenerating the cofactor NAD(P)H. [ABSTRACT FROM AUTHOR]

The utilization of biocatalytic oxidations has evolved from the niche applications of the early 21st century to a widely recognized tool for general chemical synthesis. One of the major drawbacks that hinders commercialization is the dependence on expensive nicotinamide adenine dinucleotide (NAD(P) + ) cofactors, and so, their regeneration is essential. Here, we report the design of carbon-supported Pt catalysts that can regenerate NAD(P) + by proton-driven NAD(P)H oxidation with concurrent hydrogen formation. The carbon support was modified to tune the electronic nature of the Pt nanoparticles, and it was found that the best catalyst for NAD(P) + regeneration (TOF = 581 h -1 ) was electron-rich Pt on carbon. Finally, the heterogeneous Pt catalyst was applied in the biocatalytic oxidation of a variety of alcohols catalyzed by different alcohol dehydrogenases. The Pt catalyst exhibited good compatibility with the biocatalytic system. Its NAD(P) + regeneration function successfully supported biocatalytic conversion from alcohols to corresponding ketone or lactone products. This work provides a promising strategy for chemical synthesis via NAD(P) + -dependent pathways utilizing a cooperative inorganic-enzymatic catalytic system.