Active Site Elucidation in Heterogeneous Catalysis via In Situ X-Ray Spectroscopies

Abstract

Nanostructured heterogeneous catalysts will play a key role in the development of robust artificial photosynthetic systems for water photooxidation and CO 2 photoreduction. Identifying the active site responsible for driving these chemical transformations remains a significant barrier to the design of tailored catalysts, optimized for high activity, selectivity, and lifetime. This highlight reveals how select recent breakthroughs in the application of in situ surface and bulk X-ray spectroscopies are helping to identify the active catalytic sites in a range of liquid and gas phase chemistry.

Catalysing Sustainable Fuel and Chemical Synthesis

“…The past decade has seen significant progress in understanding the fundamental mode of action of Platinum Group Metal heterogeneous catalysts for aerobic selox and the associated reaction pathways and deactivation processes [41]. This insight has been aided by advances in analytical methodologies, notably the development of in situ or operando (under working conditions) spectroscopic [52][53][54] /microscopic [55][56][57][58] tools able to provide quantitative, spatio-temporal information on structurefunction relations of solid catalysts in the liquid and vapour phase. Parallel improvements in inorganic synthetic protocols offer finer control over preparative methods to direct the nanostructure (composition, morphology, size, valence and support architecture) of palladium catalysts [59][60][61] and thereby enhance activity, selectivity and lifetime in an informed manner.…”

Perovskite Catalysts for Biomass Valorization

“…In-situ characterization techniques can also provide valuable insight into catalyst behavior under operating conditions, enabling accurate measurement of catalyst properties during reaction and hence a direct comparison between experiments performed under varying real-world conditions . X-ray absorption spectroscopy (XAS), X-ray diffraction (XRD), XPS, TEM, Raman spectroscopy, UV–vis spectroscopy, and IR spectroscopy , have all been used to characterize working catalysts.…”

Towards Global Artificial Photosynthesis (Global Solar Fuels): Energy, Nanochemistry, and Governance

“…[22] Adam Lee from Cardiff University ('Active Site Elucidation in Heterogeneous Catalysis via In Situ X-Ray Spectroscopies') similarly explores how recent breakthroughs in optic, detector, and reactor cell designs, in conjunction with global access to high energy radiation facilities, are helping in situ and bulk X-ray spectroscopies to identify and probe the active catalytic sites in wide-ranging liquid and gas phase chemistry and so assist in the development of (bio)inorganic nanostructured architectures for future solar fuel and chemicals synthesis. [23] Developing Catalysts Michael Nolan and Anna Iwaszuk from the Tyndall National Institute, and Hiroaki Tada from Kinki University ('Molecular Metal Oxide Cluster-Surface Modified Titanium (IV) Dioxide Photocatalysts'), review recent experimental and theoretical studies on the iron oxide-modified anatase/rutile and tin oxidesurface modified anatase TiO 2 photocatalysts. The former, for example, displays a narrowed band gap, giving visible light absorption compared with pure TiO 2 .…”