Assessment of transport phenomena in catalyst effectiveness for chemical polyolefin recycling.

Since the dawn of agitated brewing in the Paleolithic era, effective mixing has enabled efficient reactions. Emerging catalytic chemical polyolefin recycling processes present unique challenges, considering that the polymer melt has a viscosity three orders of magnitude higher than that of honey. The lack of protocols to achieve effective mixing may have resulted in suboptimal catalyst effectiveness.

Active learning streamlines development of high performance catalysts for higher alcohol synthesis.

Developing efficient catalysts for syngas-based higher alcohol synthesis (HAS) remains a formidable research challenge. The chain growth and CO insertion requirements demand multicomponent materials, whose complex reaction dynamics and extensive chemical space defy catalyst design norms. We present an alternative strategy by integrating active learning into experimental workflows, exemplified via the FeCoCuZr catalyst family.

The Future of Chemical Sciences is Sustainable.

Chemistry, a vital tool for sustainable development, faces a challenge due to the lack of clear guidance on actionable steps, hindering the optimal adoption of sustainability practices across its diverse facets from discovery to implementation. This Scientific Perspective explores established frameworks and principles, proposing a conciliated set of triple E priorities anchored on Environmental, Economic, and Equity pillars for research and decision making. We outline associated metrics, crucial for quantifying impacts, classifying them according to their focus areas and scales tackled.

CO Electroreduction To Syngas With Tunable Composition In An Artificial Leaf.

Invited for this month's cover is the group of Javier Pérez-Ramírez at ETH Zürich, which collaborated with the group of Tsvetelina Merdzhanova at Forschungszentrum Jülich. The image shows how artificial leaves, able to recycle carbon dioxide into syngas of variable composition, could be integrated with chemical plants. The Research Article itself is available at 10.

Consumer Grade Polyethylene Recycling via Hydrogenolysis on Ultrafine Supported Ruthenium Nanoparticles.

Catalytic hydrogenolysis has the potential to convert high-density polyethylene (HDPE), which comprises about 30 % of plastic waste, into valuable alkanes. Most investigations have focused on increasing activity for lab grade HDPEs displaying low molecular weight, with limited mechanistic understanding of the product distribution. No efficient catalyst is available for consumer grades due to their lower reactivity.

The Environmental Feasibility of Decentralised Solar Ammonia.

Intense efforts have been devoted to developing green and blue centralised Haber-Bosch processes (gHB and bHB, respectively), but the feasibility of a decentralised and sustainable scheme has yet to be assessed. Here we reveal the conditions under which small-scale systems based on the electrocatalytic reduction of nitrogen (eN2R) powered by photovoltaic energy (NH3-leaf) could become a competitive technology in terms of environmental criteria. To this end, we calculated energy efficiency targets based on solar irradiation atlases to guide research in the incipient eN2R field.

Environmental and economic potential of decentralised electrocatalytic ammonia synthesis powered by solar energy.

Intense efforts have been devoted to developing green and blue centralised Haber-Bosch processes (gHB and bHB, respectively), but the feasibility of a decentralised and more sustainable scheme has yet to be assessed. Here we reveal the conditions under which small-scale systems (NH-leaves) based on the electrocatalytic reduction of nitrogen (eNR) powered by photovoltaic energy could realise a decentralised scheme competitive in terms of environmental and economic criteria. For this purpose, we calculated energy efficiency targets worldwide, providing clear values that may guide research in the incipient eNR field.

Energy crisis in Europe enhances the sustainability of green chemicals.

Ammonia and methanol are essential to modern societies, but their production has been heavily reliant on natural gas, which contributes to supply disruptions and significant CO emissions. While low-carbon or green production routes have been extensively researched, their adoption has been hindered by higher costs, making them unsustainable. However, a recent energy crisis in Europe has created a unique opportunity to shift towards greener production technologies.

CO Electroreduction To Syngas With Tunable Composition In An Artificial Leaf.

Artificial leaves (a-leaves) can reduce carbon dioxide into syngas using solar power and could be combined with thermo- and biocatalytic technologies to decentralize the production of valuable products. By providing variable CO : H ratios on demand, a-leaves could facilitate optimal combinations and control the distribution of products in most of these hybrid systems. However, the current design procedures of a-leaves concentrate on achieving high performance for a predetermined syngas composition.

ZrO-Promoted Cu-Co, Cu-Fe and Co-Fe Catalysts for Higher Alcohol Synthesis.

The development of efficient catalysts for the direct synthesis of higher alcohols (HA) via CO hydrogenation has remained a prominent research challenge. While modified Fischer-Tropsch synthesis (m-FTS) systems hold great potential, they often retain limited active site density under operating conditions for industrially relevant performance. Aimed at improving existing catalyst architectures, this study investigates the impact of highly dispersed metal oxides of Co-Cu, Cu-Fe, and Co-Fe m-FTS systems and demonstrates the viability of ZrO as a general promoter in the direct synthesis of HA from syngas.

NMR-based quantification of liquid products in CO electroreduction on phosphate-derived nickel catalysts.

Recently discovered phosphate-derived Ni catalysts have opened a new pathway towards multicarbon products via CO electroreduction. However, understanding the influence of basic parameters such as electrode potential, pH, and buffer capacity is needed for optimized C product formation. To this end, rigorous catalyst evaluation and sensitive analytical tools are required to identify potential new products and minimize increasing quantification errors linked to long-chain carbon compounds.

Controlled Formation of Dimers and Spatially Isolated Atoms in Bimetallic Au-Ru Catalysts via Carbon-Host Functionalization.

The introduction of a foreign metal atom in the coordination environment of single-atom catalysts constitutes an exciting frontier of active-site engineering, generating bimetallic low-nuclearity catalysts often exhibiting unique catalytic synergies. To date, the exploration of their full scope is thwarted by (i) the lack of synthetic techniques with control over intermetallic coordination, and (ii) the challenging characterization of these materials. Herein, carbon-host functionalization is presented as a strategy to selectively generate Au-Ru dimers and isolated sites by simple incipient wetness impregnation, as corroborated by careful X-ray absorption spectroscopy analysis.

Microfabrication Enables Quantification of Interfacial Activity in Thermal Catalysis.

A myriad of heterogeneous catalysts comprises multiple phases that need to be precisely structured to exert their maximal contribution to performance through electronic and structural interactions at their peripheries. In view of the nanometric, tridimensional, and anisotropic nature of these materials, a quantification of the interface and the impact of catalytic sites located there on the global performance is a highly challenging task. Consequently, the true origin of catalysis often remains subject of debate even for widely studied materials.

Direct Conversion of Polypropylene into Liquid Hydrocarbons on Carbon-Supported Platinum Catalysts.

Efforts to selectively convert polypropylene (≈30 % of all plastic waste) have not been particularly successful. Typical distributions span from gas to solid products, highlighting a challenging cleavage control. Here, carbon-supported platinum nanoparticles were designed for complete hydrocracking into liquid hydrocarbons (C -C ).

Electrochemical Reduction of Carbon Dioxide to 1-Butanol on Oxide-Derived Copper.

The electroreduction of carbon dioxide using renewable electricity is an appealing strategy for the sustainable synthesis of chemicals and fuels. Extensive research has focused on the production of ethylene, ethanol and n-propanol, but more complex C molecules have been scarcely reported. Herein, we report the first direct electroreduction of CO to 1-butanol in alkaline electrolyte on Cu gas diffusion electrodes (Faradaic efficiency=0.

Hybridization of Fossil- and CO -Based Routes for Ethylene Production using Renewable Energy.

Carbon capture and utilization (CCU) has recently gained broad interest in the chemical industry. Direct electro- and thermocatalytic technologies are currently the focus of intense research, where the former employs electricity directly to reduce the CO molecule, while the latter comprises hydrogenation of CO in tandem with electrocatalytic water splitting. So far, it remains unclear which of the two is superior, yet this information is considered critical.

Nitride-Derived Copper Modified with Indium as a Selective and Highly Stable Catalyst for the Electroreduction of Carbon Dioxide.

The lack of efficient catalysts prevents the electrocatalytic reduction of carbon dioxide from contributing to the pressing target of a carbon-neutral economy. Indium-modified copper nitride was identified as a stable electrocatalyst selective toward CO. In O /Cu N showed a Faradaic efficiency of 80 % at 0.

Origin of the Selective Electroreduction of Carbon Dioxide to Formate by Chalcogen Modified Copper.

The electrochemical reduction of atmospheric CO by renewable electricity opens new routes to synthesize fuels and chemicals, but more selective and efficient catalysts are needed. Herein, by combining experimental and first-principles studies, we explain why chalcogen modified copper catalysts are selective toward formate as the only carbon product. On the unmodified copper, adsorbed CO is the key intermediate, yielding carbon monoxide and formate as carbon products.

Microfabricated electrodes unravel the role of interfaces in multicomponent copper-based CO reduction catalysts.

The emergence of synergistic effects in multicomponent catalysts can result in breakthrough advances in the electrochemical reduction of carbon dioxide. Copper-indium catalysts show high performance toward carbon monoxide production but also extensive structural and compositional changes under operation. The origin of the synergistic effect and the nature of the active phase are not well understood, thus hindering optimization efforts.

Elucidating the Distribution and Speciation of Boron and Cesium in BCsX Zeolite Catalysts for Styrene Production.

An improved understanding of the nature and distribution of boron and cesium species in BCsX zeolites is a prerequisite to guide future developments in the environmentally attractive, yet challenging, production of styrene through the side-chain alkylation of toluene with methanol. Herein, standard characterization and catalytic tests are complemented by integrated visualization through time-of-flight secondary-ion mass spectrometry and energy-dispersive X-ray spectroscopy and detailed assessment by Cs and B NMR spectroscopy, to correlate the properties and performance during successive ion-exchange and impregnation steps in the preparation of both powders and millimeter-sized granules. The results highlight a significant impact of catalyst scaleup on the effective introduction of boron species, which originates chemical heterogeneity that is linked to selectivity losses.

Building Blocks for High Performance in Electrocatalytic CO Reduction: Materials, Optimization Strategies, and Device Engineering.

In recent years, screening of materials has yielded large gains in catalytic performance for the electroreduction of CO. However, the diversity of approaches and a still immature mechanistic understanding make it challenging to assess the real potential of each concept. In addition, achieving high performance in CO (photo)electrolyzers requires not only favorable electrokinetics but also precise device engineering.

Solvothermally-Prepared Cu O Electrocatalysts for CO Reduction with Tunable Selectivity by the Introduction of p-Block Elements.

The electroreduction of CO to fuels and chemicals is an attractive strategy for the valorization of CO emissions. In this study, a Cu O electrocatalyst prepared by a simple and potentially scalable solvothermal route effectively targeted CO evolution at low-to-moderate overpotentials [with a current efficiency for CO (CE ) of ca. 60 % after 12 h at -0.

Indium Oxide as a Superior Catalyst for Methanol Synthesis by CO2 Hydrogenation.

Methanol synthesis by CO2 hydrogenation is attractive in view of avoiding the environmental implications associated with the production of the traditional syngas feedstock and mitigating global warming. However, there still is a lack of efficient catalysts for such alternative processes. Herein, we unveil the high activity, 100 % selectivity, and remarkable stability for 1000 h on stream of In2 O3 supported on ZrO2 under industrially relevant conditions.