Decarbonising energy: The developing international activity in hydrogen technologies and fuel cells.

Hydrogen technologies and fuel cells offer an alternative and improved solution for a decarbonised energy future. Fuel cells are electrochemical converters; transforming hydrogen (or energy sources containing hydrogen) and oxygen directly into electricity. The hydrogen fuel cell, invented in 1839, permits the generation of electrical energy with high efficiency through a non-combustion, electrochemical process and, importantly, without the emission of CO2 at its point of use. Hitherto, despite numerous efforts to exploit the obvious attractions of hydrogen technologies and hydrogen fuel cells, various challenges have been encountered, some of which are reviewed here. Now, however, given the exigent need to urgently seek low-carbon paths for humankind's energy future, numerous countries are advancing the deployment of hydrogen technologies and hydrogen fuel cells not only for transport, but also as a means of the storage of excess renewable energy from, for example, wind and solar farms. Furthermore, hydrogen is also being blended into the natural gas supplies used in domestic heating and targeted in the decarbonisation of critical, large-scale industrial processes such as steel making. We briefly review specific examples in countries such as Japan, South Korea and the People's Republic of China, as well as selected examples from Europe and North America in the utilization of hydrogen technologies and hydrogen fuel cells.

Providing sustainable catalytic solutions for a rapidly changing world: a summary and recommendations for urgent future action.

In addition to summarizing the main thrusts of each paper presented at this Discussion, other urgent issues involving the role (and characterization) of new catalysts for eliminating oxides of nitrogen, for using CO2 liberated from steel mills, for fuel cells and the need for rapid decarbonization of fossil fuels are outlined.This article is part of a discussion meeting issue 'Providing sustainable catalytic solutions for a rapidly changing world'.

From structure to structural dynamics: Ahmed Zewail's legacy.

In this brief tribute to Ahmed Zewail, we highlight and place in the historical context, several of the major achievements that he and his colleagues have made in Femtochemistry (of which he was the principal instigator) and his introduction of ultrafast electron scattering, diffraction, microscopy and spectroscopy. By achieving a sub-picosecond temporal resolution, coupled with a picometer spatial resolution, he revolutionised our understanding of the corpus of chemical, physical, biological and materials science systems.

The extraordinary impact of Michael Faraday on chemistry and related subjects.

Biographers of Michael Faraday, as well as many dictionaries of science, often describe him as a physicist, which he certainly was. But he was also an astonishingly effective chemist: in fact, he was the Fullerian Professor of Chemistry (at the Royal Institution, RI) from 1834 until the time of his death in August, 1867. To mark the sesquicentenary of his passing, this editorial, by one of his distant successors as Director and Fullerian Professor at the RI, focuses on Faraday's output and influence as a scientist.

The RSC Faraday prize lecture of 1989 on platinum.

In 1861, Michael Faraday gave one of his last Friday Evening Discourses at the Royal Institution of Great Britain, London, on platinum, which he described as "this beautiful, magnificent and valuable metal". More than a hundred and twenty years later (in 1989), the author re-enacted, at the Royal Institution, many of the demonstrations that Faraday carried out in his memorable Discourse. This article outlines many of Faraday's views on, and experiments with, platinum. It also describes the continuing importance and utilization of platinum, both as perceived in 1989 and from present perspectives.

Reflections on the value of electron microscopy in the study of heterogeneous catalysts.

Electron microscopy (EM) is arguably the single most powerful method of characterizing heterogeneous catalysts. Irrespective of whether they are bulk and multiphasic, or monophasic and monocrystalline, or nanocluster and even single-atom and on a support, their structures in atomic detail can be visualized in two or three dimensions, thanks to high-resolution instruments, with sub-Ångstrom spatial resolutions. Their topography, tomography, phase-purity, composition, as well as the bonding, and valence-states of their constituent atoms and ions and, in favourable circumstances, the short-range and long-range atomic order and dynamics of the catalytically active sites, can all be retrieved by the panoply of variants of modern EM. The latter embrace electron crystallography, rotation and precession electron diffraction, X-ray emission and high-resolution electron energy-loss spectra (EELS). Aberration-corrected (AC) transmission (TEM) and scanning transmission electron microscopy (STEM) have led to a revolution in structure determination. Environmental EM is already playing an increasing role in catalyst characterization, and new advances, involving special cells for the study of solid catalysts in contact with liquid reactants, have recently been deployed.

Merging Single-Atom-Dispersed Silver and Carbon Nitride to a Joint Electronic System via Copolymerization with Silver Tricyanomethanide.

Herein, we present an approach to create a hybrid between single-atom-dispersed silver and a carbon nitride polymer. Silver tricyanomethanide (AgTCM) is used as a reactive comonomer during templated carbon nitride synthesis to introduce both negative charges and silver atoms/ions to the system. The successful introduction of the extra electron density under the formation of a delocalized joint electronic system is proven by photoluminescence measurements, X-ray photoelectron spectroscopy investigations, and measurements of surface ζ-potential. At the same time, the principal structure of the carbon nitride network is not disturbed, as shown by solid-state nuclear magnetic resonance spectroscopy and electrochemical impedance spectroscopy analysis. The synthesis also results in an improvement of the visible light absorption and the development of higher surface area in the final products. The atom-dispersed AgTCM-doped carbon nitride shows an enhanced performance in the selective hydrogenation of alkynes in comparison with the performance of other conventional Ag-based materials prepared by spray deposition and impregnation-reduction methods, here exemplified with 1-hexyne.

On the dynamical nature of the active center in a single-site photocatalyst visualized by 4D ultrafast electron microscopy.

Understanding the dynamical nature of the catalytic active site embedded in complex systems at the atomic level is critical to developing efficient photocatalytic materials. Here, we report, using 4D ultrafast electron microscopy, the spatiotemporal behaviors of titanium and oxygen in a titanosilicate catalytic material. The observed changes in Bragg diffraction intensity with time at the specific lattice planes, and with a tilted geometry, provide the relaxation pathway: the Ti(4+)=O(2-) double bond transformation to a Ti(3+)-O(1-) single bond via the individual atomic displacements of the titanium and the apical oxygen. The dilation of the double bond is up to 0.8 Å and occurs on the femtosecond time scale. These findings suggest the direct catalytic involvement of the Ti(3+)-O(1-) local structure, the significance of nonthermal processes at the reactive site, and the efficient photo-induced electron transfer that plays a pivotal role in many photocatalytic reactions.

Summarizing comments on the discussion and a prospectus for urgent future action.

Following my personal reactions to some of the key points made in this Discussion (Part I), I present, in Part II, what I perceive to be the most important, and, in some cases, urgent actions that now need to be taken in the following inter-related fields: (i) design of catalysts, especially for the production of materials using anthropogenic carbon dioxide, CO2, as feedstock; (ii) the continuing role of catalysis in the protection of the environment; (iii) the importance of catalysis in the generation of fuel and the release of energy; and (iv) the wisdom of conducting life cycle and techno-economic analyses continually during the development of new catalysts, as well as of those in regular use. A brief account is also given of the prospect of designing atom-efficient catalysts in which either atomically dispersed rare (and expensive) metals such as Ir or Pt or the use of single-site earth-abundant elements (Al, Si, O) can be employed to facilitate important industrial reactions.

Sir Humphry Davy and the coal miners of the world: a commentary on Davy (1816) 'An account of an invention for giving light in explosive mixtures of fire-damp in coal mines'.

In the period between 1815 and 1818, Sir Humphry Davy read four papers to the Royal Society and published a monograph dealing with a safety lamp for coal miners, all of which record in detail the experimental work that he carried out, with his assistant Michael Faraday, so as to determine how to prevent catastrophic accidents in coal mines by the explosion of fire-damp (methane) in the presence of a naked flame. This article describes the key experiments that he performed at the Royal Institution and some of the subsequent trials made in the coal mines of the north of England. It begins, however, with an account of Davy's prior achievements in science before he was approached for help by the clergymen and doctors in the Gateshead and Newcastle upon Tyne areas. There is little doubt that the Davy lamp, from the 1820s onwards, transformed the coal industry worldwide. It also profoundly influenced the science of combustion, and in the words of a pioneer in that field, W. A. Bone, FRS, 'There is no better model of logical experimental procedure, accurate reasoning, philosophical outlook and fine literary expression.' It is a remarkable fact that it took Davy essentially only two weeks from the time he was given samples of fire-damp to solve the problem and to devise his renowned miner's safety lamp. A brief account is also given of the contemporaneous invention of a safety lamp by George Stephenson, and of some of Davy's subsequent accomplishments. This commentary was written to celebrate the 350th anniversary of the journal Philosophical Transactions of the Royal Society.

Heterogeneous catalysis and the challenges of powering the planet, securing chemicals for civilised life, and clean efficient utilization of renewable feedstocks.

This article reviews, first, the prospects, practices and principles of generating solar fuels. It does so with an analysis of recent progress in the light-driven emission of H2 (and other fuels) as well as O2 from water. To place this challenge in perspective, some current practices entailing the use of well-proven solid catalysts developed for fossil-based feedstocks, are described. The massive differences between proven methods of generating fuel and chemicals from non-renewable and from solar radiation are emphasized with the aid of numerous quantitative examples. Whilst it is acknowledged that a key action in reducing the liberation of greenhouse gases (GHG) is to tackle the challenge of decreasing their evolution in power generation and in the production of steel, aluminium and other bulk commodities (metals, alloys, concrete and ceramics), nevertheless much can be done to diminish the emission of CO2 (and to use it as feedstock) through the agency of new, designed solid catalysts and microalgae. Solar-thermal converters are also attractive alternatives, even though they are more likely to be used centrally rather than in small modular units like 'artificial leaves,' some of which are promising for the purposes of generating energy (and perhaps fuel) in a delocalized, modular manner.

The concept, reality and utility of single-site heterogeneous catalysts (SSHCs).

Very substantial advances have recently been made in the design and construction of solid catalysts and in elucidating both their mode of operation and the factors that determine their selectivity and longevity. This Perspective explains how and why such progress has been made. One important factor, the deployment of single-site heterogeneous and enzymatic catalysts, used either alone or in conjunction with other strategies, including metabolic engineering, enables a multitude of new products (for example, environmentally clean jet fuel) to be readily manufactured. In a practical sense SSHCs enable the advantages of homogeneous and to a lesser degree enzymatic catalysts to be united with those of heterogeneous ones. With the aid of the vastly increasing families of nanoporous solids, desired catalytically active sites may be engineered in atomic detail on their inner, accessible surfaces, thereby opening up new possibilities in synthetic organic chemistry - as in the smooth formation of C-C and C[double bond, length as m-dash]N bonds in a number of intermolecular reactions - as well as in photocatalysts and in fluidized catalytic cracking of hydrocarbons.

Oxidic materials: an endless frontier.

Selected areas of heterogeneous catalysis involving nanoporous oxides in the context of clean technology, green chemistry and sustainability are highlighted in this overview. So also is the potential of oxidic membranes in the context of producing hydrogen from water at high temperatures; and a brief survey is given of strategies that are required for the design of better oxidic photocatalysts for the conversion of visible light to H2 and O2. Aspects of physico-chemical characterization of advanced oxidic materials are also outlined.

Sir John Meurig Thomas.

"My greatest achievement has been to combine being a teacher, a researcher, and a popularizer of science for over 50 years. My worst nightmare is to find myself dumbstruck when I am about to give a lecture …︁" This and more about Sir John Meurig Thomas can be found on page 10938.

Efficient hydrogenation over single-site bimetallic RuSn clusters.

Hydrogenation of ethene to ethane over single-site RuN and (RuSn)N clusters is investigated using Density Functional Theory calculations. The critical transition state barrier, namely the last hydrogenation step, correlates linearly for RuN with the adsorption energies of the reactants. Addition of Sn to the Ru-clusters breaks this relation and allows for lower reaction barriers. In general, Sn is found to have pronounced effects on the geometrical and electronic properties of RuN clusters with N≤ 12. RuN clusters preferably adopt cubic conformations with high spin states, whereas (RuSn)N have low spin states and form compact Ru cores capped with Sn atoms.