Green Chemistry and Sustainable Chemical Processes: From Advanced Material Preparations to Benign-by-Design Recycling of Critical Raw Materials

Dear Colleagues,

Green chemistry is a philosophy that applies to all areas of chemistry based on a set of principles for minimizing the pollution sources and risks, together with maximizing the efficiency and selectivity of chemical reactions, according to the IUPAC definition (Pure Appl. Chem., 2000, Vol. 72, No. 7, pp. 1207–1228). Green chemistry is a paradigm-changing initiative with great potential to foster the well-being of our society and the sustainability of the planet. Implementation of green chemistry and engineering principles decreases the environmental footprint of chemical products and processes at every stage of their life cycle, together with contributing to additional economic benefits. The scope and purpose of this Special Issue are a collection of scientific and innovative investigations on the greening of conventional and employment of new emerging methods for the preparation and recycling of high-technology materials.

Presently, the climate and energy ambitions for reaching carbon neutral or “net-zero” technologies are based on the use of some strategic raw materials vital for the production of engineering materials such as catalysts, magnets, energy storage materials such as batteries, capacitors, solar cells, fuel cells and electrolyzers, carbon capture and storage, thermoelectrics, thermionics, piezoelectrics, heat exchangers, etc. While the future demand for these strategic raw materials is projected to increase dramatically, their supply chains are at risk due to their dependence on a single or a few producer countries, shortages as a result of pandemic waves, and local or global military conflicts. The so-called critical raw materials (CRMs, https://single-market-economy.ec.europa.eu/sectors/raw-materials/areas-specific-interest/critical-raw-materials_en) are indispensable for the attainment of our vision for green chemical processes and a wide range of strategic sectors, including the net zero and digital industry, healthcare and lifestyle improvement, aerospace, and defense sectors. Currently, numerous measures on achieving secure, sustainable, and competitive supply chains for CRMs have been adopted in order to implement diversification and enhance the flexibility of their supply chains, as well as to enhance their circularity and sustainability. In this regard, recycling is an important strategy for addressing CRM supply constraints in the long run, due to the environmental benefits, higher concentrations of metals of interest in the secondary ores than in the primary ones, and the increasing availability of CRM-containing scrap.

The recovery of CRMs from natural and urban ores, together with the preparation of new materials, has to reach both higher selectivity rates but also higher economic and environmental standards by following the green principal rules. The advanced material synthesis, as well as the extraction and separation of CRMs, must also reach lower energy consumption, reduced chemical consumption, and lower waste formation (both gas, liquid, and solid emissions). Nowadays, research and innovative activities are focused on the improvement of currently exploited industrial methods, together with the employment of new approaches. These emerging technologies are based on material activation before or during its synthesis or recycling (such as mechanochemical and MW methods and electrochemistry), as well as on the utilization of surfactants, supercritical fluid, molten salt, etc. These methods utilize additives or light, electricity, heat, and mechanical forces, thus achieving new reaction routes, unexpected experimental results, and significant improvement in target chemical reactions.

Thus, the ambitious goal of this Special Issue is to collect the key state-of-the-art investigation reports and review articles on the improved or new emergent methods employed toward the achievement of greener and more sustainable chemical processes with more efficient, less energy-consuming, eco-friendly, and scalable advanced material preparations or recycling of CRMs. Thus, the proposed new greener and more sustainable approaches in the recovery of CRMs from end-of-life products will pave the way toward the possibility of closing the loop of CRM recovery for their further reuse in the preparation of new high-technology products.

The forthcoming 13^th International Symposium on Heterogeneous Catalysis, 1–5 September 2024, Burgas, Bulgaria, will be a meeting point for advanced researchers and innovators, where they will share their ideas, current investigations, and achievements in the field. The synthesis and recycling of catalysts is one of the main directions of the topic, as the catalyst composition includes at least one of the most critical raw materials, mainly platinum group metals (PGMs), rare earth elements (REEs), cobalt, copper, or nickel.

For more information, please visit the event website: https://13symp.sciconf.eu/index.php/conference/general-scope.

In this Special Issue, original research articles and reviews are welcome. Research areas may include (but are not limited to) the following:

• Greening of conventional and development of new sustainable chemical processes for material synthesis or recycling;
• Benign-by-design chemical processes for synthesis of advanced materials for renewable energy production (such as hydrogen production methods and employment of wind, solar, biomass, geothermal, and hydropower energy), as well as pollution control (catalytic converters in automotive exhaust systems to reduce harmful emissions and catalysts for purification of industrial wastewater and gases);
• Critical raw materials (CRMs): challenges and sustainable solutions and CRM substitution and sustainable recycling;
• Eco-friendly and efficient chemical reactions, minimizing of waste production, and reducing the use of hazardous chemicals and water;
• Design of advanced materials toward better repair or recycling to enhance their circularity and sustainability.

I look forward to receiving your contributions.

Prof. Dr. Zara Cherkezova-Zheleva
Guest Editor

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• sustainable chemical processes
• design of advanced materials
• benign-by-design methods for material synthesis and recycling
• mechanochemistry critical raw materials (CRMs)
• CRM substitution and sustainable recycling
• eco-friendly and efficient chemical reactions
• reduction in the use of hazardous chemicals and water
• renewable energy production
• pollution control
• circularity and sustainability of materials