BIOELECTRONICS AND BIOMETALLOCATALYSIS FOR PRODUCTION OF FUELS AND CHEMICALS BY PHOTOSYNTHETIC WATER-SPLITTING

By inserting metallocatalysts (such as platinum, osmium, or ruthenium) at the reducing site of photosystem I (PSI), electrons that emerge fr om PSI can be channeled to various redox reactions that could potentia lly produce fuels and chemicals (such as H-2 and CH4, and so forth) in stead of NADP(+) reduction, as in natural photosynthesis. We have rece ntly developed a technique to photoprecipitate metallocatalysts in sit u at the reducing site of PSI in thylakoid membranes, using water-solu ble hexachloroplatinate, hexachloroosmiate, and hexachlororuthenate at biological temperature and neutral pH. This technique combined with ' 'rewiring'' of photosynthesis is a potentially important new field of biometallocatalysis. Potential applications of biometallocatalysis wil l be addressed in this article.