Preface

In Chapter 1, P. D. Muley, D. Shekhawat (National Energy Technology Laboratory, USA), Y. Wang, and J. Hu (West Virginia University, USA) provide an insight into the application of microwave heating to heterogeneous catalysis. The discussion covers the fundamentals of microwave heating, numerous applications of microwave-assisted heterogeneous catalytic reactions, technological advances, and challenges of applying microwave technology to heterogeneous catalysis. The advantages that microwave heating offers over conventional heating mechanisms include enhanced reaction rates, faster heating, modularity, rapid shutdown and start up, high product selectivity, increased catalytic activity and the opportunity to be coupled with renewable energy sources. Microwave-assisted heterogeneous catalysis shows promising potential as the next generation of catalytic reactors.

In Chapter 2, M. Andiappan, S. B. Ramakrishnan, R. T. A. Tirumala, F. Mohammadparast (Oklahoma State University, USA), T. Mou, T. Le, and B. Wang (University of Oklahoma, USA) provide a review of the current state of the art plasmonic photocatalysis through the rigorous collection of literature. The work lays the foundation by discussing the advantages of the visible-light-driven plasmonic photocatalysis over the conventional thermal energy-driven heterogeneous catalysis. Additionally, the review gives fundamental insights into photocatalytic pathways by which the catalytic activity and selectivity are enhanced on the surface of plasmonic photocatalysts. The review also delves into the computational methods used to predict and understand the photocatalytic activity and selectivity in plasmonic photocatalysis. The authors also discuss the current challenges, new opportunities, and future outlook for plasmonic photocatalysis.

In Chapter 3, Z. Zha, G. Giannakakis and P. Deshlahra (Tufts University) review studies on catalyst structure and reaction mechanisms for vinyl acetate synthesis via heterogenous non-oxidative acetylene acetoxylation and homogeneous and heterogeneous oxidative ethylene acetoxylation. In doing so, they assess the complexity and similarities in all three systems and highlight the importance of combining experiment and computation to understand the mechanisms. In spite of many studies on the method currently used in industry, heterogeneous ethylene acetoxylation, the reaction and catalyst deactivation mechanisms and the role of promoters and alloy composition are not fully resolved. Aspects of reaction mechanism involving ethylene coupling with pre-adsorbed high-coverage acetates have been established via detailed surface science and DFT work, but other essential steps for steady state catalysis describing how coverages and rate liming steps change with conditions are not well-understood. Recent kinetic, isotopic measurements and computations show that reaction orders, selectivity, and kinetic relevance of elementary steps change significantly with reactant pressures and surface coverage. Steps that account for kinetic coupling between acetate formation and consumption can fully capture these changes. Finally, they concluded that such a general mechanistic framework can guide the design and development of more active, selective, and stable catalysts for sustainable VA synthesis processes.

In Chapter 4, R. Fushimi, Y. Wang (Idaho National Laboratory, USA), and G. Yablonsky (Washington University in Saint Louis, USA) present the TAP (Temporal Analysis of Products) methodology as a unique tool using gas pulsing for systematic control of catalyst composition that at the same time provides precise kinetic characterization. The technique is compared to more commonly used kinetic tools such as the continuous stirred tank reactor and plug flow reactor for collecting kinetic data. Theoretical methods for the analysis of exit flux temporal data are discussed along with more recently developed methods for calculation of time dependent rate and concentration profiles. To highlight the utility of the tool for addressing the composition/kinetics relationship, experimental examples are presented that demonstrate surface coverage changes within one pulse response, surface evolution over the course of a multipulse sequence and changes in the context of pump/probe dynamics.

In Chapter 5, C. Khoury and O. M. Gazit (Israel Institute of Technology-Technion, Israel) and M. M. Montemore (Tulane University, USA) review the effect of a surface phase oxide (SPO) on metal support interactions (MSI) and catalysis. SPOs are thin oxide layers on a bulk substrate, often a different oxide or a metal. This chapter highlights experimental and computational findings concerning hierarchical catalysts composed of a metal supported on a SPO deposited on an underlying support. It is shown that the SPO is intrinsically different from its bulk support configuration and how the SPO state affects the properties of the supported metal and catalysis. Specific examples are given with respect to the growth of the metal, the metal electronic state, the metal stability, and the indirect effect of the underlying support. The chapter demonstrates how controlling the properties of SPO based hierarchical catalysts can be a leveraged to controlling MSI and obtaining enhanced catalytic performance in various reactions.

In Chapter 6, M. E. Martínez-Klimov, P. Mäki-Arvela and D. Y. Murzin (Åbo Akademi University, Finland) review the progress on upgradation of bio-oil. Hydrodeoxygenation (HDO) and hydrocracking (HDC) are catalytic hydrotreating processes suitable for the production of renewable jet fuel, which is mainly composed of aliphatic and aromatic hydrocarbons (C8–C16). This chapter addresses current advances in HDO of model compounds as well as real feeds over a variety of noble and transition metal catalysts. The effects of bifunctional, bimetallic and sulfided catalysts on activity and selectivity are discussed, together with the effect of support type on the reaction. High deoxygenation degree was successfully demonstrated in HDO of fast pyrolysis oil over noble metal catalysts. HDC activity of various vegetable oils is also presented, showing promising results for obtaining hydrocarbons. The industrial application of HDO and HDC of real feedstocks is still rather limited due to fast catalyst deactivation and the complexity of the feedstock itself. Ultimately, the chapter points out the future research, which addresses the challenges of catalyst stability and lowering reaction conditions through new technologies identified in existing literature, such as electrocatalysis and plasma utilization.

In Chapter 7, E. Ahmad (Indian Institute of Technology, Dhanbad, India), S. Quereshi, and K. K. Pant (Indian Institute of Technology, Delhi, India) discuss the catalytic and mechanistic insight from graphene derived 2D catalysts in biomass conversion catalysis. The application of transition metal dichalcogenides in acid catalysis and hydrodeoxygenation of biomass-derived compounds have also been discussed. In addition, growing interest in biomass conversion catalysis using other 2D catalysts such as nitrogen-doped graphene oxide, carbon nitride, metal–organic frameworks and metal carbides has been discussed with a perspective on the future research directions.

In Chapter 8, D. Kwon, C. Jo, and S.-E. Park (Inha University, Republic of Korea) outline recent achievements in the synthesis of hierarchical zeolites with bottom-up and top-down strategies and their catalytic demonstration. The benefits conferred by hierarchical structures such as improved selectivity, catalyst stability, and capability in the contexts of the reactions of bulky molecules and demonstrative applications in catalytic reactions are discussed.

In Chapter 9, S. Obregón (Autonomous University of Nuevo León, Mexico), and V. Rodríguez-González (Institute for Scientific and Technological Research of San Luis Potosi, Mexico) review one-dimensional titanate nanostructures, which exhibit better catalytic and adsorptive properties than mixed oxide materials. From the advantage of their nanotubular morphology, especially nanotubes synthesized in a one-step hydrothermal process, these nanostructures exhibit interesting surface defects, and together with their surface areas, they stand as ideal surfaces that can tailor and boost the catalytic- and photo-activity of other materials in the form of nanocomposites. Several applications of these nanostructures have been critically discussed in order to reveal their importance in the stability and high dispersion of metal nanoparticles in gas phase catalytic processes. Moreover, the use of the 1D titanates is also discussed for the photocatalytic degradation of gases (VOCs, NOx, SOx, and so on), the mineralization of aqueous drugs and organic compounds, the disinfection of microorganisms harmful to public health and to agricultural issues, as well as in the generation of alternative energy sources such as hydrogen production and CO₂ reduction, together with their adsorptive properties.

In Chapter 10, A. A. Amrute (Max Planck Institute for Coal Research, Germany, now at A*Star, Singapore) and F. Schüth (Max Planck Institute for Coal Research, Germany) review the state-of-the-art of catalytic reactions in ball mills. While mechanochemistry has been studied for a long time, catalytic reactions in ball mills are a relatively new research field, with only scattered reports dating earlier than the 2000s. In the first part of the chapter, the fundamentals of mechanochemical and mechanocatalytic systems are discussed, such as the relevance of mechanical forces for chemical reactions, the special effects brought about by ball milling, and the types of mills used, together with their advantages and disadvantages. A brief section then highlights the use of mechanochemistry for the synthesis of catalytic materials, before the major part of the chapter is focused on different types of mechanocatalytic conversions, such as solid–solid reactions, organocatalytic transformations, biomass conversion, and solid-catalyzed gas-phase reactions in mills. The chapter concludes with a perspective on in-situ analysis during milling to improve the understanding of mechanocatalytic processes. Mechanocatalysis has emerged as a highly interesting research field, which could also eventually find practical applications in industry.

In Chapter 11, H. Xin and Y. Huang (Virginia Polytechnic Institute and State University, USA) review machine learning models and their applications in catalyst design with an emphasis on heterogeneous catalysis. Examples of recent research work with various algorithms, features, and learning strategies are provided for readers to better understand this area. In addition, machine learning in homogeneous catalysis is also briefly introduced with case study examples. Finally, challenges and opportunities are discussed, and the authors believe that such outlooks will be helpful for researchers who are entering this rapidly emerging field.

In Chapter 12, Q. Zhou, J. Cai, W. Wang, Z. Liu and F. Yang (ShanghaiTech University, China; State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, China) review recent reports on the development of surface science techniques, that could measure the surface structure, electronic properties and reaction intermediates on catalytic materials during the reaction and at the spatial and temporal limit. In the past decades, tremendous efforts have been dedicated to developing surface science techniques that could be employed for in-situ studies of catalytic systems under ambient pressures, and as such to bridge the pressure gap that has generally concerned the catalysis community. In this chapter, the progress in in-situ and ambient pressure studies of catalytic reactions over well-defined model catalytic systems in the past decade is reviewed, using scanning tunnelling microscopy (STM), X-ray photoelectron spectroscopy (XPS) and Infrared reflection adsorption spectroscopy (IRAS). These advances have enabled molecular understanding of chemical processes occurring at catalytically active surfaces and interfaces. Finally, a brief outlook on developments in combining microscopic and spectroscopic surface techniques is also given, that could open a new horizon for catalytic science.

In Chapter 13, C. Feng, H. Su and J. Zeng (National Laboratory for Physical Sciences at the Microscale, CAS Key Laboratory of Strongly-Coupled Quantum Matter Physics, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, University of Science and Technology of China, China) review electrocatalysts from the fundamental concepts to application perspectives. The specific reaction mechanisms and activity descriptors of electrochemical oxygen reduction, hydrogen evolution, oxygen evolution, carbon dioxide reduction, and nitrogen reduction are discussed in detail. The introduction into each category of electrocatalysts helps to understand the structure–property relationship and provides extensive methods to improve the catalytic performance.

James J. Spivey, Louisiana State University, Baton Rouge, USA.

E-mail: [email protected]

Yi-fan Han, East China University of Science and Technology,Shanghai, China. E-mail: [email protected]

Dushyant Shekhawat, US Department of Energy, National EnergyTechnology Laboratory, USA.

E-mail: [email protected]