Applications of Ionic Liquids in Green Catalysis: A Review of Recent Efforts

: Ionic Liquids (ILs) in their neoteric form have emerged to be a potential ‘green’ alternative of traditional Volatile Organic Compounds (VOCs) as solvents in different fields of industries and academia. Recent investigations on the development of multi-faceted applications of ionic liquids have revealed that they really stand for “environmentally-benign” solvents as far as their impact on the ecology is concerned. This caused them to be an exciting and lucrative subject to explore more and more, and many research groups are involved in the manifestation of their inherent undisclosed legacy. Recently, there has been a huge jump in search of an alternative to conventional metal catalysts in academia as well as in industries due to their pollution-evoking roles. Scientists have explored multiple numbers of homogeneous or heterogeneous mixtures of catalysts incorporating ionic liquids to reduce the extent of contamination in our global environment produced due to catalytic synthesis and chemical transformations. In this review, we have put our concentration on some beneficial and recently explored aspects of the successful implementation of Ionic Liquids in different forms in several fields of catalysis as a ‘green’ alternative catalyst/co-catalyst/solvent for catalysis to replace or minimize the lone and hazardous use of metal and metallic compounds as catalysts as well as chemicals like mineral acids or VOCs as solvents. Here, our study focuses on the inevitable role of ILs in several catalytic reactions like cycloaddition of CO2, electrolytic reduction of CO2, biocatalytic or enzymatic reactions, some of the important organic conversions, and biomass to biofuel conversion as catalysts, cocatalysts, catalyst activator, and solvents.

Preface

The 2021 International Conference on Advanced Materials and Mechatronics (ICAMM 2021) was planned to be held on October 30 - November 1, 2021 in Kunming, China. Currently, the entire world is struggling against the virulent pandemic COVID-19. Unfortunately, each of us is affected, either overtly or covertly. Our conference, 2021 International Conference on Advanced Materials and Mechatronics (ICAMM 2021) was not an exception. The ICAMM 2021 was changed to be held online through Zoom software. This approach not only reduces people gathering, but also meets their communication needs. Nowadays, the research and development level and industrialization scale of advanced materials have become an important symbol to measure the economic and social development, scientific and technological progress and national defense strength of a country or region. Compared with the traditional mechanical manufacturing, the composite mechanical and electronic engineering and its technology with the introduction of artificial intelligence technology have a greater application prospect, and can meet the needs of increasingly complex industrial production and manufacturing in the era of highly developed industrial capacity. Advanced materials and mechanical and electronic mutual integration, mutual promotion, the penetration of relevant research and results affect the development of various fields in China, which is of great significance to accelerate China’s social upgrading and transformation and seize the commanding heights of a new round of scientific and technological revolution. The purpose of the conference is to build a bridge of communication for experts, scholars and personnel from all walks of life in the field of materials and electromechanics, and to help and promote the intersection and integration of different disciplines. We were greatly honored to have invited Prof.Wenhui Ma, Kunming University of Science and Technology, China and Prof. Yuanchang Zhong, Chongqing University, China to serve as our Conference Chairman. There were over 105 participants attended the meeting. During the conference, the conference model was divided into three sessions, including oral presentations, keynote speeches, and online Q&A discussion. In the first part, some scholars, whose submissions were selected as the excellent papers, were given about 5-10 minutes to perform their oral presentations one by one. Then in the second part, keynote speakers were each allocated 30-45 minutes to hold their speeches. In the second part, we invited three professors as our keynote speakers. The first one, Prof. Weidong Zhu, from University of Maryland. His research spans the fields of dynamics, vibration, control, applied mechanics, structural health monitoring, metamaterials, and wind energy, and involves analytical development, numerical simulation, experimental validation, and industrial application. Prof. Junxi Bi, Inner Mongolia University of Technology as our second keynote speaker. Prof. Xinyong Li, from Dalian University of Technology. His mainly research interests: energy catalysis, nano catalysis, green catalysis, nano science and engineering, chemistry and biosensor. Their insightful speeches had triggered heated discussion in the third session of the conference. Every participant praised this conference for disseminating useful and insightful knowledge. The proceedings of ICAMM 2021 span over 6 topical tracks, that include: Mechanics of materials, Structural mechanics, Mechanics, dynamics and its applications, Irradiation electronics, Optical/electronic/magnetic materials and other related fields. All the papers have been through rigorous review and process to meet the requirements of International publication standard. We would like to acknowledge all of those who have supported ICAMM 2021. Each individual and institutional help were very important for the success of this conference. Especially we would like to thank the organizing committee for their valuable advices in the organization and helpful peer review of the papers. The Committee of ICAMM 2021 List of Committee member are available in this pdf.

Advances in Green Catalysis for the Synthesis of Medicinally Relevant N-Heterocycles

N-heterocycles, both saturated and unsaturated, are ubiquitous biologically active molecules that are extremely appealing scaffolds in drug discovery programs. Although classical synthetic methods have been developed to access many relevant N-heterocyclic scaffolds, representing well-established and reliable routes, some do not meet the needs of sustainability. In this context, several advances have been made towards the sustainable synthesis of N-heterocycles. This review focuses on the most recent examples from the last five years of catalytic synthesis of several heterocyclic compounds of medicinal relevance. Thus, the synthesis of isoindoloquinazolines, quinazolines and azaindoles, among others, are covered. The synthetic methods selected include the use of homogeneous and heterogeneous catalysts and the use of alternative and sustainable methods such as, for example, metal-catalyzed acceptorless coupling and one-pot reactions. The green aspects of the individual synthetic approaches are highlighted, and the scope of each methodology is described.

MOF Embedded and Cu Doped CeO2 Nanostructures as Efficient Catalyst for Adipic Acid Production: Green Catalysis

Greatly efficient chemical processes are customarily based upon a catalyst activating the process pathway to achieve higher yields of a product with desired specifications. Catalysts capable of achieving good performance without compromising green credentials are a pre-requisite for the development of a sustainable process. In this study, CeO2 nanoparticles were tested for their catalytic activity with two different configurations, one as a hybrid of CeO2 nanoparticles with Zeolitic Immidazole Framework (ZIF-67) and second being doped Cu cations into CeO2 nanoparticles. Physicochemical and catalytic activity was investigated and compared for both systems. Each hybrid was synthesized by embedding the CeO2 nanoparticles into the microporous structure of ZIF-67, and Cu doped CeO2 nanoparticles were prepared by a facile hydrothermal route. As a catalytic test, it was employed for the oxidation of cyclohexene to adipic acid (AA) as an alternative to expensive noble metal-based catalysts. Heterogeneous ZIF-67/CeO2 found catalytical activity towards the oxidation of cyclohexene with nearly complete conversion of cyclohexene into AA under moderate and co-catalyst free reaction conditions, whereas Cu doped CeO2 nanoparticles have shown no catalytic activity towards cyclohexene conversion, depicting the advantages of the porous ZIF-67 structure and its synergistic effect with CeO2 nanoparticles. The large surface area catalyst could be a viable option for the green synthesis of many other chemicals.