Greener and Sustainable Chemistry

In 2015 the United Nations declared a framework comprising 17 aspirational goals known as the Sustainable Development Goals (SDGs) which was meant to be adopted by governments, industries, and other stakeholders worldwide to end poverty, protect the planet, and ensure that all people live with peace and prosperity by 2030. It can make the environment sustainable, in other words. Chemistry can play an essential role in helping society achieve the SDGs and Green Chemistry (GC) specifically may be a key player in this regard. GC complements other streams of chemistry, including environmental chemistry. Environmental Chemistry is the ‘chemistry of the environment’ that explains nature and the impact of man on nature. At the same time, GC is ‘chemistry for the environment’ i.e., more environmentally friendly chemistry. GC may be defined as “invention, design and application of chemical products and processes to reduce or eliminate the use and generation of hazardous substances”. New chemical research, green and sustainable chemistry education, green and sustainable chemical manufacturing practices, and a sense of social responsibility are critical for all chemists worldwide as we work together to protect our planet Earth. SDGs including Zero Hunger, Good Health and Well-being, Clean Water and Sanitation, Affordable and Clean Energy, Industries, Innovation and Infrastructure, Responsible Consumption and Production, Climate Action is directly related to chemistry at large and GC in precise. Therefore, if we rightly practice GC, it serves the purpose of environmental sustainability and will be useful in achieving the SDGs, which will ensure that all people enjoy peace and prosperity in the long run. Green Chemistry Education is quite important in this regard, which needs to be practiced more and more.

The first Special Topic issue devoted to green chemistry was published in Pure and Applied Chemistry in July 2000 [Pure Appl. Chem.72, 1207-1403 (2000)]. Since then, three collections of works have been published, arising from the recently launched IUPAC series of International Conferences on Green Chemistry:- 1st International Conference on Green Chemistry (ICGC-1), Dresden, Germany, 10-15 September 2006: Pure Appl. Chem.79, 1833-2100 (2007)- 2nd International Conference on Green Chemistry (ICGC-2), Moscow, Russia, 14-20 September 2008: Pure Appl. Chem.81, 1961-2129 (2009)- 3rd International Conference on Green Chemistry (ICGC-3), Ottawa, Canada, 15-18 August 2010: Pure Appl. Chem.83, 1343-1406 (2011)This Special Topic issue forms part of the series on green chemistry, and is an outcome of IUPAC Project No. 2008-016-1-300: “Chlorine-free Synthesis for Green Chemistry” previously announced in Chemistry International, May-June, p. 22 (2011).The IUPAC Subcommittee on Green Chemistry was founded in July 2001 and has selected the following definition for green chemistry [1]: “The invention, design and application of chemical products and processes to reduce or to eliminate the use and generation of hazardous substances” [2].Much controversy persists about the appropriate terminology to describe this new field of research. Which term should be selected, “green chemistry” or “sustainable chemistry”? Perhaps consensus can be achieved if different purposes and interests of chemists are reconciled. If we are involved in fundamental research devoted to the discovery of new reaction pathways and reagents, “green” is the best word because it defines these intents, thus the term “green chemistry” would be the best name for this field of research. If we are interested in exploitation of a process or a product that must be profitable, then such chemical manufacture must be sustainable by many criteria (price, competition, profit, environment, etc.), and, accordingly, “sustainable chemistry” is the term that best defines this objective.This Special Topic issue has been designed with the intent to explore the restriction, or preferably prevention, of the use of halogenated compounds, whenever feasible, through the assembly and reporting of already identified information. This intent has been pursued through innovative synthetic pathways using clearly identified production drivers (e.g., energy consumption, environmental impact, economical feasibility, etc.). In past decades, scientific knowledge and feasible technologies were unavailable, but we now have enough expertise to pursue discontinuation of hazardous and toxic reagents. In fact, the replacement of reagents that are toxic, dangerous, and produced by eco-unfriendly processes is still an underdeveloped area of chemistry today.Pietro TundoProject Co-chair1. For a short history of green chemistry, see: P. Tundo, F. Aricò. Chem. Int.29(5), (2007).2. P. Anastas, D. Black, J. Breen, T. Collins, S. Memoli, J. Miyamoto, M. Polyakoff, W. Tumas, P. Tundo. Pure Appl. Chem.72, 1207 (2000).

Recent years have seen a disheartening string of revelations in which everyday items once considered safe—food packaging, toys, clothes, furniture, electronic components, and many more products—are found to contain carcinogens, endocrine disruptors, and other harmful chemicals.1 Growing demand for healthier alternatives, already seen in food production and housing construction,2 is also happening at the building-block level of manufacturing, where so-called green chemistry represents a revolutionary change in preventing pollution and health problems starting at the chemical design stage. Many industry and government entities are beginning to espouse the principles of green chemistry on their websites and in public statements. Now comes the task of crafting policy to put those principles into action. The U.S. Environmental Protection Agency (EPA) defines green chemistry as “the design of chemical products and processes that reduce or eliminate the use or generation of hazardous substances. Green chemistry applies across the life cycle of a chemical product, including its design, manufacture, and use.”3 Green chemistry also aims to mitigate the type of uncertainty Alan Gold-berg, a professor of toxicology at the Johns Hopkins Bloomberg School of Public Health, recently described to The New York Times: “I can get [toxicity] information on only 20 percent of chemicals we interact with on a daily basis.”4 Of that 20%, he now says, he may be able to find information on overt toxicity for about half, but for details on specific effects such as developmental neurotoxicity, the figure shrinks toward zero. So what does green chemistry look like? Consider the example of pregabalin, the active ingredient in the neuropathic pain drug Lyrica®. Pfizer developed an alternative green-chemistry process that converted several steps of pregabalin synthesis from use of organic solvents to water. That reduced both health hazards and production heating requirements. With the new synthesis, waste from the process dropped from 86 kg of waste per kg product to 17 kg, and energy use dropped by 82%.5 Proponents say that’s how the field can offer a win–win–win solution: good performance, lower cost, and less environmental impact—what Richard Engler, program manager of the EPA Green Chemistry Program, calls the “triple bottom line.” For many, a standard is a logical next step. “At some point you have to go beyond a definition and principles,” says Engler. “I think that’s something the standard will enable.”

Catalyst has a noteworthy role in chemical processes in both industrial and scientific fields. Use of catalyst can helps to serve less energy, time and money. As a result, chemical process became more eco-friendly and economical. Nanocatalysts are an important branch in this issue. Multicomponent reactions (MCRs) are one of the most effective strategies in the field of green chemistry; witch is the utilization of a set of principles that reduces or eliminates the use or generation of hazardous substances in the design, manufacture, and application of chemical products. Therefore, by application of nanocatalysts in MCRs, chemical synthesis can approach aims of green and sustainable chemistry. As it is mentioned nanocatalyst, are important field and have many advantages in recent years. Magnetic nanocatalysts are a subdivision of catalyst and beneficial strategy in green chemistry. Biocatalysts are another one either. Meet of these two branches results a new, efficient and green nanocatalyst. Chitosan is a biopolymer and it is used in many organic syntheses as catalyst, supporting this with a magnetic nanocatalystmodified this biocatalyst and enhance its properties, also leads to another efficient and green catalyst.

Copyright: © 2012 Varma RS. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Industrial chemistry in the new millennium is widely embracing the concept of “green chemistry” to meet the fundamental scientific challenges of protecting the human health and environment while maintaining commercial success. This emerging area of Green Chemistry is defined as “the utilization of a set of principles that reduces or eliminates the use or generation of hazardous substances in the design, manufacture, and application of chemical products” and envisages minimum hazard as the performance criteria while designing new chemical processes. One of the thrust areas for achieving this target is to explore the generation of efficient catalytic processes, particularly nano-catalysis [1]. The desired approach may encompass alternative activation methodology, such as mechanochemical mixing, photocatalysis, microwave-, and ultrasonic irradiation [2]. Additionally, the strategy has to follow “benign by design” principles and make an effort to utilize renewable resources wherever possible [3].

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] Green Chemistry, also called as Sustainable Chemistry, envisions minimum hazard to improve the efficiency and performance of materials while designing new chemical processes. In general, Green Chemistry is defined as " ... the utilization of a set of principles that reduces or eliminates the use or generation of hazardous substances in the design, manufacture, and application of chemical products."[1] In recent decades, there is widespread recognition of the need to adopt cleaner, sustainable practices to enhance the quality and control of commercial products through a knowledge based approach. The goal for the researchers in sustainable chemistry is to meet the objective without compromising the basic needs of future generations. Nanotechnology, much like Green Chemistry, has revolutionized the fundamentals of all fields, serving as a classic example for emerging products in science and technologies. Despite significant achievements involving nanomaterials, the hazardous chemicals and toxicities associated with them are not fully addressed, which causes a major impact on the environment. These phenomena were especially observed for the use of nanocatalysts. Several greener approaches were utilized to produce nanomaterials or nanoparticles, which avoids toxic reducing agents such as borohydrides or hydrazine. However, chemists need to develop simple and cost-effective approaches for sustainable nanocatalysts to meet global challenges. The overall focus of this doctoral dissertation has been paid to the synthesis, controlled surface modification, and functionalization of distinct types of nanoparticles and nanocomposites through sustainable chemical approaches for environmental and biological applications. As a two-dimensional material, molybdenum disulfide (MoS2) has drawn wide attention due to its fascinating properties and exciting application prospects. However, in order to access these properties, which lie within single- or few-layer nanosheets, the inter-sheet van der Waals interactions within the bulk material must be adequately disrupted to exfoliate MoS2 to atomic thicknesses. Chapter 2 present the sonication-assisted aqueous phase exfoliation of bulk MoS2 into dispersed single- or few-layer nanosheets using popular culinary hydrocolloids. In addition, the sterically stabilized nanosheets were successfully decorated with gold nanoparticles via an in-situ reduction by the hydrocolloids to yield plasmonic nanocomposites exhibiting excellent catalytic activity in 4-nitrophenol (4-NP) reduction. Chapter 3 describes one-pot aqueous photo-assisted route to produce tailored metal nanoparticles decorated aminoclay nanosheets. This method uses no heating or external reducing agent (e.g., NaBH4) nor is photocatalyst required. Finally, these nanohybrids were tested as a dual catalyst for 4-NP reduction or antimicrobial activity. Layered transition metal dichalcogenides (TMDs) have attracted increased attention due to their enhanced hydrogen evolution reaction (HER) performance. Chapter 4 accounts the successful synthesis of few-layered MoS2/rGO, SnS2/rGO, and (MoS2)x(SnO2)1-x/rGO nanohybrids anchored on reduced graphene oxide (rGO) through a facile hydrothermal reaction in the presence of ionic liquids (ILs) as stabilizing, delayering agents. Linear sweep voltammetry measurements reveal that incorporation of Sn into the ternary nanohybrids (as a discrete SnO2 phase) greatly reduces the overpotential by 90--130 mV relative to the MoS2 electrocatalyst. The hierarchical structures and large surface areas possessing exposed, active edge sites make few layered (MoS2)x(SnO2)1-x/rGO nanohybrids promising nonprecious metal electrocatalysts for the HER. Conventional ILs have detectable vapor pressures, however, they are still insignificant near ambient temperatures compared with traditional molecular solvents. In Chapter 5, a simple, straightforward, and reliable isothermal gravimetric measurements were conducted on various ILs, deep eutectic solvents (DES), polymeric ionic liquids, protic ionic liquids, and molecular solvents to estimate their vapor pressures with high accuracy. The vapor pressure of ILs and DESs are in the range of 0.1 - 30 Pa at 100 - 250 [degrees]C and 3 - 161 Pa at 60 - 160 [degrees]C, respectively. Moreover, our study elucidates the trends in vapor pressure and ionic constituent's role. Based on the vapor pressure data, an investigator can readily design specific fluids on the mode of applications. In Chapter 6 reports a template-free strategy to attain a hierarchically mesoporous carbon from the cyclotrimerization of alkyne-functionalized ionic liquids (AFILs) as carbon precursors paired with paramagnetic anions. Thus, the current AFILs are shown to be viable precursors to porous carbon materials with several interesting applications, including the sorption of dyes (cationic methylene blue (MB) and anionic thiazine red R (TRR)) from a contaminated aqueous stream and their subsequent degradation by employing the Fenton reaction. In particular, the mesoporous carbons were successfully applied as a selective adsorbent for separation of binary-dye mixtures (MB + TRR). Importantly, the Fe-AFILs@C can be easily removed from the aqueous solution after sorption process, and can be easily regenerated with a simple ethanol-washing step.

Green chemistry, environmentally benign chemical synthesis, alter­ native synthetic pathways for pollution prevention, benign by design: these phrases all essentially describe the same concept. Green chemistry is the utilization of a set of principles that reduces or eliminates the use or generation of hazardous substances in the design, manufacture and application of chemical products. Green chemistry is not complicated although it is often elegant. It holds as its goal nothing less then perfection, while recognizing that all of the advances and innovations towards this goal will contain some discrete risk. It is through these continual incremental improvements that the objectives of green chemistry will be realized. Chemists have always striven for efficiency in their synthetic methodologies. To be able to conduct a transformation or construct a pathway to a molecule effectively and reliably was fundamental to the art of the synthetic chemist. Efficiency is important, not only as a measure of the quality of a synthetic method, but also as a practical and economic consideration as well. Economic considerations have played a major role in designing syntheses that use the most available and/or lowest cost feedstock.

Catalysis as a foundational pillar of green chemistry

New research on reduction and/or elimination of hazardous substances in the design, manufacture and application of chemical products

Modern chemistry is one of the essential tools in pursuing better medical care, more efficient telecommunications and informatics, and increased agricultural production. However, certain chemicals produced and used in large quantities might cause various hazards in environmental sectors, owing to their global (trans-boundary) translocation, as well as their intrinsically hazardous properties. To reduce environmental risk of such chemicals, international regulatory measures have already been taken [e.g., in response to the initiatives of the Intergovernmental Forum in Chemical Safety (IFCS)], including legally binding implementations and national capacity building in developing countries. Herein lies the urgent need for promoting worldwide research into green chemistry (sustainable chemistry), in which the invention and application of chemical products and processes are designed to reduce or to eliminate the use and generation of hazardous substances. Indeed, green chemistry should encompass a variety of disciplines of fundamental chemistry in IUPAC, to encourage new trends of chemical research. Moreover, results of these researches could be effectively applied for solving environmental problems related to the production and use of chemicals and to create a new chemical industry in the future. As such, green chemistry research conforms completely to the mission-oriented activity of IUPAC to meet regulatory requirements for achieving environmentally sound management of chemicals. We sincerely hope that the present special issue highlighting the state of the art and future prospects of green chemistry research will encourage all chemists who intend to serve society through their research efforts. J. Miyamoto Past-President of IUPAC Chemistry and the Environment Division The increasing knowledge in natural sciences and the application of this knowledge are the driving forces for the development and welfare of mankind. Chemistry plays a central role in this development. Chemistry provides the molecular understanding of physical properties of materials and other matters and thus closely interacts with physics. Chemistry also provides the molecular understanding of living systems and is the basis for modern biology and medicine. The development and opportunities of synthetic chemistry have opened a new dimension for tailor-made materials and compounds for specific purposes. The driving forces for developments in chemistry have been very strong, and there is a demand for new and efficient processes and chemicals. Aspects of sustainable and environmentally friendly processes and chemicals have sometimes been lagging behind this demand. Fortunately, chemistry also provides the tools for a green and sustainable development. Knowledge in this general area has to be integrated into the planning of all research and development in chemistry. There are specific research topics related to the development of green and sustainable processes, which need the input of new technology and novel chemistry. The present Symposium-in-Print provides an overview of recent research and development in the field. We hope that it will stimulate further activities in the field. It is planned as a first step in an IUPAC action on this subject. The IUPAC Organic and Biomolecular Chemistry Division is grateful to its Subcommittee on Organic Synthesis and particularly Professor Pietro Tundo for initiating and engaging in this action, and to him and Profs. David StC. Black and Sofia Memoli for editing the Symposium-in-Print. Torbjörn Norin President of IUPAC Organic and Biomolecular Chemistry Division

Defined in the 1990s as the “design of chemical products and processes that reduce or eliminate the use and generation of hazardous substances”, green chemistry, and the companion concept green engineering, currently represent important social, cultural, philosophical, and practical tools for achieving sustainability. (1) Both green and sustainable chemistry and engineering can broadly reach and interconnect different aspects of our society, and therefore, it is of utmost importance in addressing and tackling the 17 United Nations Sustainable Development Goals (UN SDGs) and their associated targets. (2,3) To promote peace, protect our planet, and end poverty by 2030, the systemic change enabled by the holistic and inclusive perspective of green and sustainable chemistry and engineering is essential. Within this context, women and girls occupy a unique position: (1) They are disproportionally more impacted by the consequences of climate change and pollution. (4) (2) They are excluded when comes time to build solutions, through the continued lack of gender equity in research, in innovation, and in power-holding positions. (3) They have been shown to be positive and ethical agents of change, whose exclusion may slow the inception of necessary sustainable solutions. Gender inequity is currently recognized as a prominent barrier to sustainable development; out of the 232 unique indicators toward the UN SDGs progress, 54 are classified as gender indicators. (5) The UN SDG 5 (Gender Equality) is also acknowledged as central and will compromise the fulfillment of all other goals if not achieved. (5,6) Women are important agents of change whose contributions in economic, social, and environmental systems are crucial for the achievement of a sustainable future (Figure 1). In this editorial, written on the occasion of the 2022 International Women’s Day, we want to make the case for how a more systematic integration of women within all aspects of green and sustainable chemistry and engineering is paramount to preserving and improving our planet.

Environment is under constant threat by unprecedented anthropogenic pressures, linear economy models for manufacturing leading to unabated challenges of pollution, waste management, climate change, carbon footprint, and sustainability at large. Though socioeconomic trends have witnessed an escalating trend attributed to industrialization in first place, an upward trend of multifaceted “waste” accumulation and hazardous materials has instigated environmentalists, academics, policymakers, scientists, and industrialists to think of circular/atomic economy models. This approach would necessarily delineate best waste management practices with multidimensional approach utilizing principles of green chemistry as a makeover shift culminating not only into environmental sustainability but also viable waste to wealth paradigm shift. Green chemistry is aptly referred to as environmentally benign chemistry with an arduous task to identify, investigate, monitor, mitigate and remediate the diversified nature of “contaminants” and contaminated sites; dispersed and accumulated in different ecosystems posing adverse eco-toxicological implications. Technically, green chemistry encompasses a set of principles aimed to address challenges to reduce and minimize generation of waste products and hazardous substances in design, manufacturing, and application of chemical products. This comprehensive account discusses green chemistry practices for effective waste management as an integrated approach from industrial (commercial), health care settings (biomedical waste), and municipal (domestic) waste view point.

In recent years the terms “green chemistry” or “sustainable development” have become more popular as a new approach to chemical production around the world. Green chemistry is an expression of a set of principles that reduce or eliminate the use, production and release of hazardous substances during the production and application of chemical products. The article provides an explanation of the 12 principles of green chemistry proposed by the American scientist Anastas in 1988. At the same time, it highlights how to follow these principles during the complex processing of mineral raw materials. It is shown that traditional existing technologies do not meet the principles of modern “green chemistry” in the complex processing of difficult-to-enrich ores and selective concentrates. The article compares the processing of raw materials by pyro and hydrometallurgical methods and shows the advantages of the latter method. A collection and analysis of literature and articles related to modern problems of green chemistry was carried out. Finally, an assessment of the processing of 4 mineral resources (polymetallic sulfide ore, alunite ore, arsenic-containing cobalt ore waste and copper ore) existing in the territory of our Republic using green chemistry principles was carried out and an analysis of how to use these principles with technological schemes was given

We are grateful to Environmental Health Perspectives for implicitly embracing green chemistry as a field with profound connections to the environmental health sciences. We also commend the efforts of Wilson and Schwarzman (2009) to create greater transparency and accountability around chemicals of concern. We take issue, however, with their approach to key scientific concepts and terminology—specifically their effort to change the definition of “green chemistry.” Precision in terminology is paramount for science to function; all parties to a scientific discussion must share the same set of definitions for knowledge to advance effectively. In their review, Wilson and Schwarzman (2009) ignored the original and current definition of green chemistry, which for almost two decades has been recognized as a scientific discipline within the field of chemistry. Defined in the early 1990s by the U.S. Environmental Protection Agency (2009) as “the design of chemical products and processes that reduce or eliminate the use or generation of hazardous substances,” green chemistry is now guided by a set of 12 principles (Anastas and Warner 1998) that are used in both research and teaching in chemis try laboratories around the world. Based on these principles, dozens of universities around the world teach green chemistry as a science. Seven graduate programs offer degrees in green chemistry. Two established peer-reviewed scientific journals focus specifically on research in green chemistry. The impact factor of the journal Green Chemistry (published by the Royal Society of Chemistry) has increased from 2.5 to almost 5 over the past 5 years. More than 1,500 articles on green chemistry have been published in the scientific literature over the past 15 years. Rather than embracing green chemistry’s widely used scientific definition, Wilson and Schwarzman (2009) instead conflate science and policy: The laws governing the chemical enterprise help define the incentives and disincentives that guide economic behavior in the market …. We use the term green chemistry in this context: as an analytical framework that encompasses both the science of safer chemistry and the laws and policies that will motivate its development and adoption by society. This conflation brings with it two risks. First, it undermines clarity in scientific communication, something that is especially important as the fields of environmental health and green chemistry attempt to establish cross-disciplinary collaboration. Such collaborations are likely to prove vital for both fields. Second, it saddles the intellectual and scientific enterprise of green chemistry with policy and, potentially, political baggage, as considerations of chemical policies unfold in the political arena. We are most certainly not arguing that the science of green chemistry should not inform chemical policies. Science and policy will be more effective, however, if political actors do not muddy accepted scientific terminology in service of a political/policy agenda, no matter how noble.

Green chemistry is the utilization of a set of principles that will help reduce the use and generation of hazardous substances during the manufacture and application of chemical products. Green chemistry aims to protect the environment not by cleaning up, but by inventing new chemical processes that do not pollute. It is a rapidly developing and an important area in the chemical sciences. Principles of green chemistry, developments in this field and some industrial applications are discussed.