Chemoselective NADH Regeneration: the Synergy Effect of TiO<sub><i>x</i></sub> and Pt in NAD<sup>+</sup> Hydrogenation
Maodi Wang, Xiaomin Ren, Miao Guo, Jiali Liu, He Li, Qihua Yang
Abstract
The regeneration of the reduced form cofactor nicotinamide adenine dinucleotide (NADH) by NAD+ hydrogenation is an economical way for the practical application of biocatalysis but still remains a big challenge due to the low selectivity. Herein, we report that the selectivity to NADH could be greatly promoted by the strong metal–support interaction effect between Pt and TiO2. It was found that NADH selectivity determined by enzyme analysis increased with Pt/TiO2 reduction temperature increasing and reached a maximum of 63.4% at a reduction temperature of 450 °C. The catalysis and characterization results revealed that Pt is the active site for H2 activation and dissociation and TiOx is responsible for the preferential adsorption of NAD+ through amide C═O. The selective NAD+ hydrogenation to NADH is assisted by hydrogen spillover. The prevention of the direct adsorption of NAD+ on Pt sites is necessary to obtain high NADH selectivity, which provides a new designable idea for selective NAD+ hydrogenation.