Bio-inspired oxygen evolving light driven catalysts (BOLDCATS)

The major challenge in the area of renewable energy is devise sustainable ways of making fuels, preferably dense portable fuels that can be used for applications such as aviation. There is one major biochemical/chemical process on Earth that can use solar energy to make fuels and this is photosynthesis. The problem, however, of using photosynthesis (P/S) directly to make fuels (biofuels) is the rather low efficiency of conversion of solar energy into fuel. However, if it were possible to 'tap into' P/S at the level of the primary reactions then, in principle, higher energy conversion efficiencies are possible. This is the idea behind the drive for artificial photosynthesis using a strategy that breaks it down into 4 partial reactions. Worldwide there has been a lot of work designed to understand the molecular details of these key four steps in photosynthesis . There has been excellent progress in understanding steps 1 and 2, indeed there are now many artificial reaction centre and antenna mimics that function rather well. The major barriers to building systems capable of using solar energy to make fuels are our current inability to produce robust catalysts that can split water and use the reductant produced to synthesise a fuel. The main aims of this proposal are to work towards the production of novel devices that can overcome these barriers.

In this CRP we aim to develop novel light-driven water splitting devices capable of providing reducing equivalents for the reduction of carbon dioxide into formate as the first step towards producing a fuel. We will focus on comparing the use of PS1 and PS2 isolated from the thermophilic cyanobacterium Thermosynechococcus elongatus with that of inorganic bio-mimetic analogues. The biological samples provide functioning modules that will be used to develop working systems while the more robust chemical analogues are being designed and synthesised. One side of the cell uses light to split water (PS2) the other uses PS1 and light to reduce CO2 to formate that can later be converted into methanol. In this context the production of formate is just an exemplar for being able to demonstrate light-driven reduction of carbon dioxide. The two sides of the cell are separated so that the PS1 side can be kept anaerobic since formate dehydrogenase is oxygen sensitive. Formate dehydrogenase (FDH) from Syntrophobacter fumaroxidans has been shown to be functional when coupled to a patterned glass electrode system.

nsuring a stable energy supply is the central challenge of the 21st century, and this team will highlight the importance of the problem and prepare the next generation of scientists. In additional to the technical goals, this project is envisaged to have broader impacts in four distinct domains:

1. The successful completion of the scientific goals of this program will transform thinking about photosynthesis by creating independent modules for studying and optimizing the light and dark processes as well as portable biowires to establish functional contacts between distinct cell types. These modules, as well as the platform for testing them as a system, will be freely shared with other researchers.

2. The RAs will be important stakeholders in team and the proposed project offers extraordinary training opportunities to RAs at all levels. Unique to this project and multidisciplinary team is the range of scientific disciplines and academic institutions involved.

3. The BOLD-CATS team exemplifies the globalization of science and will serve as a model for collaboration in the EU.

4. Dissemination of scientific results will be crucial to this project, both to push the boundaries of photosynthetic research and engage the public in understanding a crucial problem. The geographic location of the participants provides a unique opportunity to develop web-based photosynthetic resources to engage the international community.