The development of molecular water oxidation catalysts

Abstract

There is an urgent need to transition from fossil fuels to solar fuels -not only to lower CO2 emissions that cause global warming, but also to ration fossil resources. Splitting H2O with sunlight emerges as a clean and sustainable energy conversion scheme that can afford practical technologies in the short to midterm. A crucial component in such a device is a water oxidation catalyst (WOC). These artificial catalysts have mainly been developed over the last two decades, which is in contrast to Nature's WOCs, which have featured in its photosynthetic apparatus for more than a billion years. This time period has seen the development of increasingly active molecular WOCs, the study of which affords an understanding of catalytic mechanisms and decomposition pathways. This Perspective offers a historical description of the landmark molecular WOCs, particularly ruthenium systems, that have guided research to our present degree of understanding.

Mimicking the Catalytic Center for the Water-Splitting Reaction in Photosystem II

“…Due to its significantly fundamental interests and potential applications, the investigation of the OEC has attracted extensive attention during the last several decades. A long-standing goal in science seeks to reveal the structure-function relationship and the catalytic mechanism of the OEC, which would provide a blueprint to develop efficient artificial catalysts for the water-splitting reaction in artificial photosynthesis [2,7,9,10].…”

Insights into the Suzuki‐Miyaura Reaction Catalyzed by Novel Pd−Carbene Complexes. Are Palladium−Tetra‐ carbene Entities the Key Active Species?

“…[11] Due to the good stability and coordination capability, pyridyls serve as N-ligands for some transition metal-catalyzed reactions, especially redox reactions. [12,13] In addition, as an alternative to phosphines, the remarkably strong σ-binding and π-backdonation characters, steric tunability and high stability under oxidative conditions of N-heterocyclic carbene (NHC) ligands, provide them the ability to stabilize highly unusual and hitherto elusive reactive species such as metal nanoparticles. [14,15] Nevertheless, despite the PdÀ NHC complexes have been considered as robust catalysts, the MÀ NHC bond is susceptible to facile cleavage by reactions of reductive elimination, protonolysis and ligand displacement, which prompts to unravel the modus operandi of such systems.…”

Catalysis of a Single Transition Metal Site for Water Oxidation: From Mononuclear Molecules to Single Atoms

“…Sunlight is by far the amplest renewable energy resource on the Earth. Over billions of years, plants and organisms in nature have been utilizing sunlight to be self‐sustaining and to provide oxygen and foods to human beings as well as other animals through photosynthesis . Inspired by nature, artificial photosynthesis systems have been elaborately devised to produce useful fuels using water as the reaction medium, such as splitting of water to hydrogen energy, or the direct conversion of carbon dioxide to liquid fuels .…”