Progress and Prospective of Nitrogen-Based Alternative Fuels

Crystalline metal-organic frameworks (MOFs) are formed by reticular synthesis, which creates strong bonds between inorganic and organic units. Careful selection of MOF constituents can yield crystals of ultrahigh porosity and high thermal and chemical stability. These characteristics allow the interior of MOFs to be chemically altered for use in gas separation, gas storage, and catalysis, among other applications. The precision commonly exercised in their chemical modification and the ability to expand their metrics without changing the underlying topology have not been achieved with other solids. MOFs whose chemical composition and shape of building units can be multiply varied within a particular structure already exist and may lead to materials that offer a synergistic combination of properties.

Nitrogen is fundamental to all of life and to many industrial processes. Nitrogen in its various oxidation states comprises the global nitrogen cycle, with the change between forms being redox reactions involving electrons and protons. The interchange of nitrogen oxidation states constitutes some of the most important industrial processes, with the energy for these processes being provided largely by fossil fuel. A key goal of research in the field of nitrogen chemistry is to minimize the use of fossil fuels by developing more efficient heterogeneous, homogeneous, or biological catalysts, or by inventing new energy-efficient processes that rely on catalysts. These approaches, as well as the challenges involved, are discussed in this review. This review article reports on the current state of the field of nitrogen activation chemistry and discusses future directions.