Increasing the stream of recycled plastic necessitates an approach beyond the traditional recycling via melting and re‐extrusion. Various chemical recycling processes have great potential to enhance recycling rates. In this Review, a summary of the various chemical recycling routes and assessment via life‐cycle analysis is complemented by an extensive list of processes developed by companies active in chemical recycling. We show that each of the currently available processes is applicable for specific plastic waste streams. Thus, only a combination of different technologies can address the plastic waste problem. Research should focus on more realistic, more contaminated and mixed waste streams, while collection and sorting infrastructure will need to be improved, that is, by stricter regulation. This Review aims to inspire both science and innovation for the production of higher value and quality products from plastic recycling suitable for reuse or valorization to create the necessary economic and environmental push for a circular economy.

The production of high-demand chemical commodities, such as ethylene and propylene (methanol-toolefins), hydrocarbons (methanol-to-hydrocarbons), gasoline (methanol-to-gasoline) and aromatics (methanol-to-aromatics) from methanol-obtainable from alternative feedstocks, such as carbon dioxide, biomass, waste or natural gas through the intermediate formation of synthesis gas-has been central to research in both academia and industry. Although discovered in the late 1970s, this catalytic technology has only been industrially implemented over the last decade, with a number of large commercial plants already operating in Asia. However, as it is the case for other technologies, industrial maturity is not a synonym of full understanding. For this reason, research is still intense and a number of important discoveries have been reported over the last few years. In this review, we summarize the most recent advances in mechanistic understanding-including direct CC bond formation during the induction period and the promotional effect of zeolite topology and acidity on the alkene cycle-and correlate these insights to practical aspects in terms of catalyst design and engineering.

T he reduction of CO 2 emissions into the Earth's atmosphere is gaining legislative importance in view of its impact on the climate [1][2][3][4][5] . Reduction of the harmful effect of these emissions through reclamation of CO 2 is made attractive because CO 2 can be a zero-or even negative-cost carbon feedstock 6,7 . The conversion of renewably produced hydrogen and CO 2 into methane, or synthetic natural gas, over Ni is a solution that combines the potential to reduce CO 2 emissions with a direct answer to the temporal mismatch in renewable electricity production capacity and demand [8][9][10][11][12][13][14][15][16][17] . Chemical energy storage in the form of hydrogen production by electrolysis is a relatively mature technology; however, the required costly infrastructure, and inefficiencies in distribution and storage deem it inconvenient for large-scale application in the near future. Point-source CO 2 hydrogenation to methane represents an alternative approach with higher energy density. Furthermore, methane is more easily liquefied and can be stored safely in large quantities through infrastructures that already exist 18,19 . Power-to-gas (in this case methane) is thus actively considered as being capable of balancing electric grid stability, which will allow us to increase the renewable energy supply 20 .The search for fossil fuel alternatives, and application of a process such as that described above can arguably be achieved only with the help of advances in catalysis and the closely related field of nanomaterials. Continuous efforts in both fields have allowed us to make increasingly smaller and catalytically more active (metal) particles. However, it is already known that making progressively smaller supported catalyst particles does not necessarily linearly correspond to higher catalytic activity [21][22][23] . This phenomenon, where not all atoms in a supported metal catalyst have the same activity, is called structure sensitivity and is often attributed to the distinctly different chemistries on different lattice planes for π -bond activation in CO 2 , or σ -bond activation in, for example H 2 dissociation and C-H propagation 21,24 . The availability of stepped (less coordinated) versus terrace (more coordinated) sites on the surface of supported catalyst nanoparticles obviously changes with particle size, and atomic geometries become particularly interesting below 2 nm where, for example, π -bond activation is believed to not be able to occur 21 . While particle-size effects have been extensively studied for CO hydrogenation over Co 23,25 , the understanding of such structure sensitivity effects for these critical smaller metal particle sizes is lacking as sub-2-nm particles prove difficult to synthesize for first-row transition metals (Co, Fe and Ni). However, a particle-size effect for CO 2 hydrogenation is much less well established 26 .Here, we used a unique set of SiO 2 -supported Ni nanoparticles with diameters ranging from 1 to 7 nm in size, and show not only the existence of a distinct pa...

The ability to probe morphology and phase distribution in complex systems at multiple length scales unravels the interplay of nano-and micrometer-scale factors at the origin of macroscopic behavior. While different electron-and X-ray-based imaging techniques can be combined with spectroscopy at high resolutions, owing to experimental time limitations the resulting fields of view are too small to be representative of a composite sample. Here a new X-ray imaging set-up is proposed, combining full-field transmission X-ray microscopy (TXM) with X-ray absorption near-edge structure (XANES) spectroscopy to follow two-dimensional and three-dimensional morphological and chemical changes in large volumes at high resolution (tens of nanometers). TXM XANES imaging offers chemical speciation at the nanoscale in thick samples (> 20 mm) with minimal preparation requirements. Further, its high throughput allows the analysis of large areas (up to millimeters) in minutes to a few hours. Proof of concept is provided using battery electrodes, although its versatility will lead to impact in a number of diverse research fields.

Transmission X-ray microscopy (TXM) has been well recognized as a powerful tool for non-destructive investigation of the three-dimensional inner structure of a sample with spatial resolution down to a few tens of nanometers, especially when combined with synchrotron radiation sources. Recent developments of this technique have presented a need for new tools for both system control and data analysis. Here a software package developed in MATLAB for script command generation and analysis of TXM data is presented. The first toolkit, the script generator, allows automating complex experimental tasks which involve up to several thousand motor movements. The second package was designed to accomplish computationally intense tasks such as data processing of mosaic and mosaic tomography datasets; dual-energy contrast imaging, where data are recorded above and below a specific X-ray absorption edge; and TXM X-ray absorption near-edge structure imaging datasets. Furthermore, analytical and iterative tomography reconstruction algorithms were implemented. The compiled software package is freely available.