HYDROGEN STORAGE PROJECT
Hydrogen is presently seen as a strong contender to be the next major fuel source for energy generation, supplementing and perhaps eventually replacing our current reliance on fossil fuels. In order for hydrogen to be a practical alternative to fossil fuels, efficient and effective hydrogen storage and release mechanisms need to be realized. Effective hydrogen storage and generation have been highly researched and debated topics as a result of i) current limitations of storage vessels to allow small footprint fuel tanks, and ii) these storage methods require complicated systems to regulate the safe release of the high pressure hydrogen in small and controlled quantities. Currently, hydrogen is produced through steam reformation of hydrocarbons, which requires very high temperatures and produces large amounts of carbon monoxide and carbon dioxide. The production of hydrogen from dehydrogenation represents an intriguing idea where small saturated molecules are decomposed under very mild conditions to unsaturated molecules and hydrogen. The fusion of the ideas of dehydrogenation, hydrogen generation, and nanoporous coordination polymers (NCPs) to provide catalytic NCPs which contain highly active dehydrogenation catalysts could solve the problems associated with hydrogen generation and storage. The approach of using NCPs as architectures for more complex molecules, specifically transition metal catalysts, could have a very broad impact in the field of energy generation.
Hydrogen gas distinguishes itself from other fuel feedstocks owing to its high energy density and the fact that its only combustion byproduct is water. Nevertheless, effective hydrogen storage and generation has been met with limited success. Current limitations relate to the lack of adequate storage vessels, which require complicated methods to regulate the safe release of the high pressure hydrogen in controlled quantities. Another issue is the lack of energy-efficient solutions for hydrogen generation. The principle mode of producing hydrogen is through the steam reformation of hydrocarbons, which produces large amounts of greenhouse gases and, most importantly, requires more energy to produce than it generates upon combustion. The production of hydrogen from alkane feedstocks represents an intriguing idea, whereby saturated small-molecules are decomposed under very mild conditions to produce unsaturated compounds and hydrogen gas. Although these reactions have been known for some time, they employ delicate, unpredictable and relatively inactive transition metal complexes. Newly developed technologies in the form of NCPs could potentially address these stability issues by providing a scaffold that offers an environment to protect the catalyst active site. One example is the use of known alkene metathesis catalysts to produce higher molecular weight hydrocarbons from very low molecular weight ones. This advance would effectively allow for the production of gasoline from gases such as propane.
The goal of this project is to synthesize small molecule catalysts that perform alkane dehydrogenation and olefin cross metathesis, but also possess functional handles that allow them to be incorporated into a single NCP in a facile manner. This post-synthetically modified NCP will generate hydrogen from natural gas and use the resulting olefins to produce light naphtha via olefin cross metathesis. This process would yield a single material that can produce a clean fuel while providing a steady carbon feedstock for the synthesis of fine chemicals. The proposal described herein offers simple and practical solutions towards developing hydrogen storage and generation technology over the next couple of years. The advantages offered by this promising technology, however, go far beyond the mere production of fuels for automobiles. The products generated by this process also serve as feedstocks for polymers and fine chemicals. By exposing a simple component of natural gas, such as butane, to a catalyst that performs dehydrogenation, we would liberate one molecule of hydrogen to be used for fueling an automobile, and one molecule of 1-butene, which can serve as a raw material for the manufacture of fine chemicals and polymers.