Department of Chemistry, Princeton University, Princeton, NJ 08544, USA.
Proc Natl Acad Sci U S A. 2013 Feb 5;110(6):2017-22. doi: 10.1073/pnas.1215149110. Epub 2013 Jan 22.
Certain bacterial enzymes, the diiron hydrogenases, have turnover numbers for hydrogen production from water as large as 10(4)/s. Their much smaller common active site, composed of earth-abundant materials, has a structure that is an attractive starting point for the design of a practical catalyst for electrocatalytic or solar photocatalytic hydrogen production from water. In earlier work, our group has reported the computational design of FeFe/FeS(2), a hydrogenase-inspired catalyst/electrode complex, which is efficient and stable throughout the production cycle. However, the diiron hydrogenases are highly sensitive to ambient oxygen by a mechanism not yet understood in detail. An issue critical for practical use of FeFe/FeS(2) is whether this catalyst/electrode complex is tolerant to the ambient oxygen. We report demonstration by ab initio simulations that the complex is indeed tolerant to dissolved oxygen over timescales long enough for practical application, reducing it efficiently. This promising hydrogen-producing catalyst, composed of earth-abundant materials and with a diffusion-limited rate in acidified water, is efficient as well as oxygen tolerant.
某些细菌酶，即双铁氢化酶，其水分解产氢的周转率高达 10(4)/s。它们较小的常见活性位点由丰富的地球材料组成，其结构是设计用于电催化或太阳能光催化水分解产氢的实用催化剂的一个有吸引力的起点。在早期的工作中，我们的小组已经报道了FeFe/FeS(2)的计算设计，这是一种受氢化酶启发的催化剂/电极复合物，在整个产氢循环中都具有高效和稳定的性能。然而，双铁氢化酶的机制还没有被详细理解，对环境氧非常敏感。对于FeFe/FeS(2)的实际应用来说，一个关键问题是该催化剂/电极复合物是否能耐受环境氧。我们通过从头计算模拟报告证明，该复合物确实能耐受溶解氧，其时间尺度足以满足实际应用，并且能有效地还原溶解氧。这种由丰富的地球材料组成的、在酸化水中扩散速率受限的、有前景的产氢催化剂不仅高效，而且还能耐受氧气。
