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.

Figure 1. (a) The 5 edge-transitive topologies for 2D COFs. (b) The 6 topologies with 3 kinds of vertices and 2 kinds of edges. Communication pubs.acs.org/JACS

A new mode of mechanical entanglement in extended structures is described where 1D organic ribbons of cornersharing squares are mutually interlocked to form 3D woven covalent organic framework-500, COF-500. Reaction of aldehydefunctionalized tetrahedral Cu(PDB)2PO2Ph2 complexes (PDB = 4,4'-(1,10-phenanthroline-2,9-diyl)dibenzaldehyde) with rectangular tetratopic ETTBA ((ethene-1,1,2,2-tetrayl)tetrakis([1,1'-biphenyl]-4-amine)) linkers through imine condensation, yielded a crystalline porous metalated COF, COF-500-Cu, with pts topology. Upon removal of the Cu(I) ions, the individual 1D square ribbons in the demetalated form (COF-500) are held together only by mechanical interlocking of rings that allows their collective movement to produce a narrow-pore form as evidenced by nitrogen adsorption and solid-state photoluminescence studies. When exposed to tetrahydrofuran vapor, the interlocking ribbons can dynamically move away from each other to reopen up the structure. The structural integrity of COF-500 is maintained during its dynamics because the constituent square ribbons cannot part company due to spatial confinement imparted by their interlocking nature.

Metal sintering and carbon deposition are acknowledged to be the foremost critical issues in the important energy storage process of high temperature Dry Reforming of Methane (DRM). For that process, so-called "core-shell catalysts" have exhibited outstanding catalytic performance. However, the intrinsic confined geometric space of the host core-shell structure not only inevitably limits the ability of the catalyst system to facilitate the critical rapid infusion and diffusion of reacting gases, but also enhances the accompanying conversion of carbon intermediates to inert, catalystdeactivating carbonaceous deposits under high-space-velocity conditions. Herein, we present a study highlighting the importance of the inner cavity space, now of a quasizero-dimensional, tubular, yolk-shell structured Ni@SiO2 nanocapsule catalyst, in the DRM process. The tubular yolk-shell structured Ni@SiO2 nanocapsule catalysts having controlled inner cavities (5.0-13.0 nm × 5.0-50.0 nm dimensions) were synthesised via a water-in-oil micro-emulsion method by employing different aging times (i.e. 3 h, 6 h and 12 h). Compared with corresponding Ni@SiO2 nanosphere catalysts, the tubular nanocapsule catalysts displayed both excellent catalyst activity, stability, and (metal) anti-sintering ability with, equally important, negligible carbon deposition during the 2 operating DRM process under high space velocity conditions (60 L g-1 h-1), most relevant for application in real industrial processes.