Besisa Nada H A, Yoon Ki-Seok, Yamauchi M
Department of Chemistry, Graduate School of Science, Kyushu University Fukuoka 819-0395 Japan
International Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu University Fukuoka 819-0395 Japan.
Chem Sci. 2024 Jan 16;15(9):3240-3248. doi: 10.1039/d3sc04104b. eCollection 2024 Feb 28.
Nicotinamide adenine dinucleotide (NAD) and its reduced form (NADH) are key cofactors serving as essential hydrogen acceptors and donors to facilitate energy and material conversions under mild conditions. We demonstrate direct electrochemical conversion to achieve highly efficient regeneration of enzymatically active 1,4-NADH using a Pt-modified TiO catalyst grown directly on a Ti mesh electrode (Pt-TOT). Spectral analyses revealed that defects formed by the inclusion of Pt species in the lattice of TiO play a critical role in the regeneration process. In particular, Pt-TOT containing approximately 3 atom% of Pt exhibited unprecedented efficiency in the electrochemical reduction of NAD at the lowest overpotential to date. This exceptional performance led to the production of active 1,4-NADH with a significantly high yield of 86 ± 3% at -0.6 V Ag/AgCl (-0.06 V RHE) and an even higher yield of 99.5 ± 0.4% at a slightly elevated negative potential of -0.8 V Ag/AgCl (-0.2 V RHE). Furthermore, the electrochemically generated NADH was directly applied in the enzymatic conversion of pyruvic acid to lactic acid using lactate dehydrogenase.
烟酰胺腺嘌呤二核苷酸（NAD）及其还原形式（NADH）是关键的辅酶，作为重要的氢受体和供体，在温和条件下促进能量和物质的转化。我们展示了直接电化学转化过程，利用直接生长在钛网电极（Pt-TOT）上的铂修饰二氧化钛催化剂实现了具有酶活性的1,4-NADH的高效再生。光谱分析表明，在二氧化钛晶格中引入铂物种形成的缺陷在再生过程中起关键作用。特别是，含有约3原子百分比铂的Pt-TOT在电化学还原NAD时表现出前所未有的效率，过电位为迄今为止最低。这种卓越的性能使得在-0.6 V Ag/AgCl（-0.06 V RHE）时能够以86±3%的显著高产率生成活性1,4-NADH，在稍高的负电位-0.8 V Ag/AgCl（-0.2 V RHE）时产率甚至更高，达到99.5±0.4%。此外，电化学产生的NADH直接应用于利用乳酸脱氢酶将丙酮酸酶促转化为乳酸的过程中。
