Single-Atom Catalysis: A Forthcoming Revolution in Chemistry

By Mario Pagliaro

Single-Atom Catalysis: A Forthcoming Revolution in Chemistry reviews the latest developments, including whether or not this technology can become a technically and economically viable choice and whether existing challenges can be overcome to encourage its uptake. Beginning with an introduction to single-atom catalysis and current developments in the field, the book then reviews its role in potentially disruptive technologies, with a particular focus on applications in synthetic organic chemistry, solar hydrogen technologies and low platinum/platinum-free fuel cells.

Other sections cover the steps needed for single-atom catalysis to become an industrially viable technology and its future outlook. Based on the extensive experience of its award-winning author, this book provides an authoritative guide on this novel approach.

• Explains the applications of single-atom catalysis in synthetic organic chemistry, solar hydrogen technologies and low platinum/ platinum-free fuel cells
• Updates on recent research developments in this emerging area
• Anticipates technical and economic challenges in the integration of single-atom catalysis

• Language: English
• Publisher: Elsevier Science
• Release date: May 17, 2019
• ISBN: 9780128190890

Mario Pagliaro

Mario Pagliaro is a chemistry and energy scholar based at Italy's Research Council in Palermo, Italy, where he leads a research group focusing on nanochemistry, sustainability and the bioeconomy. Rapidly approaching 10,000 citations as of early 2019, he ranks amongst Italy’s most cited scientists in nanotechnology and materials science. In recognition of his "significant contributions to the chemical sciences" in 2014 he was designed Fellow of the Royal Society of Chemistry. His work has been widely highlighted by national and international press, including by MIT Technology Review, Advanced Science News, Italy’s national television, newspapers and magazines. He also serves on the advisory and editorial boards of several internationally recognized journals.

Book preview

Single-Atom Catalysis

A Forthcoming Revolution in Chemistry

Mario Pagliaro, PhD

Istituto per lo Studio dei Materiali Nanostrutturati, CNR, Palermo, Italy

Table of Contents

Cover image

Title page

Copyright

Dedication

Foreword

Preface

Acknowledgments

About the Author

Chapter 1. Introduction to Single-Atom Catalysis

Single-Atom Catalysis

The Unique Features of Atomically Dispersed Catalysts

Synthetic Routes to Single-Atom Catalysts

Observing Single-Atom Catalysts

Watching Single-Atom Catalysts In Situ

Chapter 2. The Role of Single-Atom Catalysis in Potentially Disruptive Technologies

A Disruptive Technology?

Synthetic Organic Chemistry

Solar Ammonia: Electrocatalytic Synthesis From Nitrogen and Water

Hydrogen Peroxide via Oxygen Reduction

Solar Hydrogen

Low-Cost Hydrogen Fuel Cells

The Key Role of China in the Solar Hydrogen Economy

Chapter 3. Can Single-Atom Catalysis Be an Industrially Viable Technology?

Innovation in Catalysis: A Practical Insight

An Industry in Transition

Customer-Driven Innovation

Stable and High-Load Single-Atom Catalysts

Fostering Innovation in Single-Atom Catalysis

The Unique Methodology of Chemistry

An Updated Look on Molecules

Single Atoms in Physics and Single Atoms in Chemistry

Advancing Catalysis Education

Index

Copyright

SINGLE-ATOM CATALYSIS   ISBN: 978-0-12-819088-3

Copyright © 2019 Elsevier Inc. All rights reserved.

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Notices

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Dedication

To David Avnir,

giant of chemistry,

for his many discoveries,

for the benefit of mankind.

Foreword

Single-atom catalysis emerged in recent times as a most relevant and powerful alternative to catalysis using nanoentities (e.g., nanoclusters, nanoparticles) that has been already proved to provide various remarkable advantages in laboratory-scale reactions as illustrated in this monography.

The possibilities and applications of these exciting and rather challenging design systems range from classic heterogeneously catalyzed processes to solar/photocatalytic reactions, with promising prospects for a potential future industrial implementation.

The full potential of single-atom catalysts (SACs) is yet to be realized, as these materials still have a long way to go in terms of practical/industrial implementation. Nevertheless, this book provides a critical and updated insight, which will be beneficial to catalysis practitioners in academia as well as in industry for years to come.

Students and young researchers willing to work in the field will find in this book the starting point, succinctly providing them with a unified picture of SACs within the overall context of catalysis science and technology. I will personally use the book to teach my students in Spain and abroad.

Consider the book as a not-to-be-missed starting point for a fundamental understanding of the design of single-atom systems of chemical relevance (see the brilliant discussion of the conceptual difference of single-atom systems in chemistry and in physics in the Chapter 3), including their forthcoming practical applications.

Most importantly, indeed, this book has a unique and unprecedented practical/industrial viewpoint that hopefully will also serve to stimulate further research and industrial interest in future widespread implementation of these exciting systems in commercial processes. The book is certainly a step forward in that direction.

Following two decades of dramatic fundamental and applied advances, catalysis is living a true renaissance, whose impact and scope will be similar to the advances of the first decades of the past century, when most chemical productions based on catalytic processes were established and industrialized in the context Mario Pagliaro calls the solar economy.

The biorefinery, the water electrolyzer, and the hydrogen fuel cell, which are the three main technologies of the said emerging economy, will all greatly benefit from newly developed SACs replacing today's conventional catalysts. After reading this book, I am convinced that SACs will play an essential role in the new chemical industry based on biological resources as well as in fuel cell electric vehicles, including trains and ships, soon to become ubiquitous.

The author deserves to be congratulated for having been able to provide a coherent picture of a booming field of today's chemical research, while avoiding the inevitable rapid obsolescence of all too many state-of-the-art outlooks in the rapidly developing fields of scientific research.

With very best wishes for an enjoyable reading!

Rafael Luque,     2018 Highly Cited Researcher, Universidad de Cordoba, Spain

Preface

Often in academia researchers solve in a very elegant manner nonexistent problems. And I believe it's true commented Matthias Beller, an eminent chemistry scholar, in an interview given on receiving an award for research in catalysis in 2016. ¹

This holds true also for catalysis regardless of its central role in the chemical industry wherein 95% of all products (volume) are synthesized via catalytic processes. In detail, around 80% of all catalytic processes use heterogeneous catalysts, 15% use homogeneous catalysts, and 5% use biocatalysts. ²

However, we argue in this book devoted to the latest and potentially disruptive catalysis technology that the chemical industry and its $18–20 billion sector whose market is divided into four main areas (industrial and automobile environmental catalysts, chemistry catalysts, petroleum refining catalysts, and polymerization catalysts) ² is about to face profound changes following the closely related energy industry.

Driven by the need to end unsustainable dependence on oil due to conflicting economics, oil supply, and population dynamics, ³ renewable energy obtained from photovoltaic (PV) modules and wind and hydroelectric turbines has lately emerged as an economically viable alternative to fossil fuel energy.

Thanks to a decade of exceptional growth of the PV and wind power installed worldwide, which led to booming industrial production and falling prices, generating electricity from PV modules and wind turbines at no fuel cost has become cheaper than burning coal, which is the cheapest fuel. ⁴

Electricity storage is, therefore, the missing technology to achieve the full transition to renewable energy. ⁵

In brief, in the emerging renewable energy scenario, which is reshaping the global energy industry, the volatile (and large) demand of energy that is met today in many countries by the combination of energy production from sun, wind, and water (renewable energy sources, RES) and from fossil energy sources (FES, Eq. 1) will be met by renewable energy using new electricity storage technologies (Eq. 2):

(1)

(2)

Progress in storage has been dramatic and the Li-ion battery and hydrogen fuel cell are emerging as the key enabling technologies suitable for large-scale deployment to power vehicles and buildings, as well as for utility-scale grid storage applications. ⁶

The overall outcome will be energy that is, at the same time, cheap, clean, and reliable.

Solar hydrogen obtained from water via water electrolysis and water splitting by concentrated solar power is the clean and versatile fuel with which mankind will store intermittent renewable electricity on the scale and scope required by the global transition to renewable energy. ⁷

Single-atom catalysts (SACs), we argue in Chapter 2, will soon be used in the anodes and cathodes of commercial hydrogen fuel cells and water electrolyzers.

Readers may remember how, until a few years ago, intense research efforts were devoted to develop materials capable of chemically storing hydrogen. Progress in composite science and technology has been so rapid that nowadays hydrogen-powered cars, trains, boats, and trucks all use H2 safely stored at 350 or 700   bar pressure in composite pressure vessels.

Similarly, it is the generalized adoption of smart digital control technologies in renewable energy generation, storage, and utilization devices that allows to maximize clean energy production and utilization. ⁸

All equipped with digital control technology, tomorrow's fuel cells and water electrolyzers, we argue in the book, will make use of SACs in conjunction with the aforementioned advanced new materials.

For example, in a fruitful synergy first demonstrated by Tour and coworkers in 2015, the exceptional electron mobility of graphene was aptly exploited using (nitrogen-doped) graphene as the support of catalytically active single Co atoms, resulting in a single-atom electrocatalyst for water electrolysis with unprecedented performance and durability. ⁹

The second chemical technology that will be reshaped by single-atom catalysis is chemical manufacturing. The impact of single-atom catalysis industrialization will be particularly significant in two fields that have remained a niche in the chemical industry, namely, electrocatalysis and photocatalysis. Photocatalysis will be applied in new-generation biorefineries to synthesize chemicals and polymers starting from the new abundant and renewable raw materials of the chemical industry: lignocellulosic biomass, water, and air.

Industrial processes that are more than a century old, such as the Fritz-Haber process for the synthesis of ammonia, or close to being a century old, such as the Riedl-Pfleiderer process to make hydrogen peroxide, now have SAC-based alternatives (Chapter 2) that are actively being explored to replace huge ammonia and hydrogen peroxide plants with a distributed network of much smaller plants running on efficient electrocatalytic processes using low cost and durable SACs.

Fine chemicals and pharmaceuticals are also more easily and economically manufactured under flow using single-site catalysts in place of homogeneous or conventional nanoparticle catalysts in which, even in mesoporous silica with surface area exceeding 600   m²/g embedding and protecting from sintering 8-nm   Pd nanoparticles, two-thirds of the palladium surface atoms are actually blocked by the silica shell. ¹⁰

The industrial renaissance of innovation in catalysis will be rapid and will result in several new catalysis companies adding to the more than 15 international companies producing about 100 fundamental types of solid catalysts surveyed by Hagen in 2015. ²

Along with new biocatalysts, industry will demand new heterogeneous catalysts combining the high selectivity of homogeneous catalysts with the well-known technical advantages of catalytic materials.

The practical introduction of SACs in the bulk and fine chemical industry implies to satisfy two main technical requirements identified in Chapter 3, along with an insight into process innovation in the chemical industry that will benefit chemistry innovators working on the development of SACs aimed