Contributions of inorganic chemistry to energy research

There is surely no more pressing objective for the scientific community than to develop technologies for the sustainable provision of energy? The reliance on finite fossil fuel reserves and the likely causal link between CO₂ emissions and climate change are seemingly at odds with the aspirations of a growing World population to maintain and improve living standards, and a desire for energy security at a national level. Given the importance of this area, it is little wonder (but nevertheless of concern) that a cacophony of self-interest and politics can often seem to silence sound science. There are few other areas of science and technology that are as likely to appear on the front pages of newspapers. Plans for off-shore wind turbines, building new nuclear reactors, colossal (and colossally expensive) experimental reactors for controlled nuclear fusion – these are just some of the stories which have been recent lead items on news bulletins.

The University of Bristol is located just a few miles from the estuary of the River Severn. This estuary is historically maritime Bristol's link to the rest of the World. It is notoriously difficult to navigate for ships’ captains because it has one of the largest tidal ranges of anywhere on the globe (some 14.5 meters). This accident of geography also makes the Severn Estuary a pre-eminent site for sustainable tidal power generation; a 10-mile long barrage is estimated to deliver up to 5% of the entire UK energy requirement. The debate whether to build such a barrage has now been going on, with more or less urgency, for over 100 years and looks likely to continue. Environmental factors, such as changes to the sensitive habitats along the estuary, are subtle and complex. Economic considerations are similarly difficult to pin down. What is certain is that actually building this scheme would be one of the most challenging (and costly) engineering projects ever undertaken.

In contrast to these few, large engineering projects, is the steady and less-obtrusive growth of renewables at the community or household scale. Such installations may be vastly smaller in scale but they are large in number and growing at a remarkable rate. The introduction of feed-in-tariffs (FIT) for small-scale renewable energy generation has led to a surge in new installations, particularly of photovoltaics. The UK has seen around four times the rate of domestic photovoltaic installation since FIT was introduced last year, replicating trends seen in earlier FIT adopters such as Germany and Spain. Such subsidies however are intended as a stimulus to reduce costs and will be withdrawn over time. Technology developments are expected and needed to take up the slack and ultimately make renewables fully competitive. Added to this is the continued problem of energy storage. What role will new batteries, capacitors, chemical fuels and fuel cells have to play in the renewable future?

Against this backdrop of engineering mega-projects and government stimulus on a vast scale, an issue of an international journal for inorganic chemistry dedicated to energy research could seem rather parochial. How can the chemistry reported in Dalton Transactions compete for headlines with taming seas, mimicking conditions in the heart of the sun or a landscape changed by solar panel covered roofs? What role for the chemist in this most-crucial of areas? These questions are well-answered by browsing the chemistry described in this themed issue. Inorganic chemistry is critical to a huge swathe of emerging and existing energy technologies; advances in science within the remit of Dalton Transactions are likely to be at the heart of solving many aspects of this problem. Included are articles describing the conversion of sunlight to usable energy, not just by improved photovoltaic materials but also through photocatalytic water splitting; the catalytic conversion of biomass-derived substrates, often derived from the waste of other processes (bio-synthesis gas from a variety of green waste, glycerol as a by-product of biodiesel manufacture); the utilisation of carbon dioxide via catalytic transformation to valuable products; materials for hydrogen storage; studies into uranium chemistry that will help separations and waste storage in the nuclear industry.

What is also impressive is that these articles cover the widest range of inorganic chemistry: main group, transition series and f-block; solid state and solution; fundamental studies and application. Materials synthesis and characterisation is central to solar cells. Coordination chemistry also has a role to play in this specific field, as it does with the elements relevant to the nuclear industry. Materials, coordination and organometallic chemistry all impact catalysis, whether homogeneous or heterogeneous. The work described in this themed issue focuses more explicitly on catalysis research to produce fuels, be it hydrogen or liquid fuels for transportation. But the entire area of catalysis research is, of course, fundamentally about reducing energy consumption, either directly by using milder reaction conditions or downstream by higher selectivity removing the requirement for separations.

So, is the importance of energy research in chemistry overlooked in comparison to the projects described in the first part of this editorial? Perhaps. It is maybe an aspect of human nature to desire a single, big solution to a problem, when the real answer is likely to lie in a multitude of smaller solutions. What is certain is that chemists will not solve these problems in isolation, and collaboration with other disciplines is essential to deliver real, operable technology. Previous themed issues of Dalton Transactions have covered certain topics of energy research, notably concerned with nanomaterials for alternative energy sources (2008) and solar energy conversion (2008 and 2009). However, we believe bringing all aspects of relevant research together in one issue is useful in showcasing the outstanding contribution the entire inorganic chemistry community is continuing to make in this area.

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