The ubiquitous challenge of plastic waste has led to the modern descriptor 'plastisphere' to represent the human-made plastic environment and ecosystem.Here we report a straightforward, rapid method for the deconstruction of various plastic feedstocks into hydrogen and high-value carbons. We use microwaves together with abundant and inexpensive iron-based catalysts as microwavesusceptors to initiate the catalytic deconstruction process. The one-step process typically takes some 30-90 seconds to transform a sample of mechanically-pulverised commercial plastic into hydrogen and (predominantly) multi-walled carbon nanotubes. A high hydrogen yield of 55.6 mmol• − is achieved, with over 97 % of the theoretical mass of hydrogen being extracted from the deconstructed plastic. The approach is demonstrated on widely used, real-world plastic waste. This proof-of-concept advance highlights the potential of plastics waste itself as valuable energy feedstocks for the production of hydrogen and high-value carbon materials.

With mounting concerns over climate change, the utilisation or conversion of carbon dioxide into sustainable, synthetic hydrocarbons fuels, most notably for transportation purposes, continues to attract worldwide interest. This is particularly true in the search for sustainable or renewable aviation fuels. These offer considerable potential since, instead of consuming fossil crude oil, the fuels are produced from carbon dioxide using sustainable renewable hydrogen and energy. We report here a synthetic protocol to the fixation of carbon dioxide by converting it directly into aviation jet fuel using novel, inexpensive iron-based catalysts. We prepare the Fe-Mn-K catalyst by the so-called Organic Combustion Method, and the catalyst shows a carbon dioxide conversion through hydrogenation to hydrocarbons in the aviation jet fuel range of 38.2%, with a yield of 17.2%, and a selectivity of 47.8%, and with an attendant low carbon monoxide (5.6%) and methane selectivity (10.4%). The conversion reaction also produces light olefins ethylene, propylene, and butenes, totalling a yield of 8.7%, which are important raw materials for the petrochemical industry and are presently also only obtained from fossil crude oil. As this carbon dioxide is extracted from air, and re-emitted from jet fuels when combusted in flight, the overall effect is a carbon-neutral fuel. This contrasts with jet fuels produced from hydrocarbon fossil sources where the combustion process unlocks the fossil carbon and places it into the atmosphere, in longevity, as aerial carbon - carbon dioxide.

Hydrogen as an energy carrier promises a sustainable energy revolution. However, one of the greatest challenges for any future hydrogen economy is the necessity for large scale hydrogen production not involving concurrent CO production. The high intrinsic hydrogen content of liquid-range alkane hydrocarbons (including diesel) offers a potential route to CO -free hydrogen production through their catalytic deep dehydrogenation. We report here a means of rapidly liberating high-purity hydrogen by microwave-promoted catalytic dehydrogenation of liquid alkanes using Fe and Ni particles supported on silicon carbide. A H production selectivity from all evolved gases of some 98 %, is achieved with less than a fraction of a percent of adventitious CO and CO . The major co-product is solid, elemental carbon.

Microwave-stimulated catalytic dehydrogenation of fossil hydrocarbon fuels allows for the rapid production and safe storage of hydrogen.

The thermodynamics of jet fuel range alkane synthesis from carbon dioxide and hydrogen has been investigated. The hydrocarbon synthesis process is divided into three elementary steps, including light olefins formation (C2‐C6) from hydrogenation of CO2, α‐olefins (C7‐C16) synthesis from oligomerization of light olefins, and hydrogenation of α‐olefins (C8‐C16) to straight‐chain paraffin (C8‐C16). The enthalpy changes and Gibbs free energy changes of the relevant reactions were calculated, and the equilibrium products distribution was computed based on the Gibbs free energy minimization method. The calculation results show that lower temperature (below 673.15 K), higher pressure (3 MPa), higher molar ratio of H2 to CO2 (3:1‐4:1), and introducing a small amount of N2 in the reactants are favorable for the hydrogenation of CO2; lower temperature (below 500 K), higher pressure (2‐3 MPa), addition of N2 is favorable for the oligomerization of light olefins; and lower temperature (below 700 K), higher pressure (2‐3 MPa), and addition of N2 is favorable for the hydrogenation of α‐olefins. The overall positive effect of introducing N2 results from its heat dilution of the process. © 2017 Society of Chemical Industry and John Wiley & Sons, Ltd.

Hydrogen is often described as the fuel of the future, especially for application in hydrogen powered fuel-cell vehicles (HFCV’s). However, its widespread implementation in this role has been thwarted by the lack of a lightweight, safe, on-board hydrogen storage material. Here we show that benign, readily-available hydrocarbon wax is capable of rapidly releasing large amounts of hydrogen through microwave-assisted catalytic decomposition. This discovery offers a new material and system for safe and efficient hydrogen storage and could facilitate its application in a HFCV. Importantly, hydrogen storage materials made of wax can be manufactured through completely sustainable processes utilizing biomass or other renewable feedstocks.

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With the rapid development of industrial society and humankind’s prosperity, the growing demands of global energy, mainly based on the combustion of hydrocarbon fossil fuels, has become one of the most severe challenges all over the world. It is estimated that fossil fuel consumption continues to grow with an annual increase rate of 1.3%, which has seriously affected the natural environment through the emission of greenhouse gases, most notably carbon dioxide (CO2). Given these recognized environmental concerns, it is imperative to develop clean technologies for converting captured CO2 to high-valued chemicals, one of which is value-added hydrocarbons. In this article, environmental effects due to CO2 emission are discussed and various routes for CO2 hydrogenation to hydrocarbons including light olefins, fuel oils (gasoline and jet fuel), and aromatics are comprehensively elaborated. Our emphasis is on catalyst development. In addition, we present an outlook that summarizes the research challenges and opportunities associated with the hydrogenation of CO2 to hydrocarbon products.