Electrocatalytic and Photocatalytic Hydrogen Production in Aqueous Solution by a Molecular Cobalt Complex

Abstract

Ein einkerniger Cobalt‐Komplex mit einem neuartigen fünfzähnigen Liganden (siehe Bild) katalysiert die Entwicklung von Wasserstoff in ausschließlich wässriger Lösung. Der Komplex könnte als Elektro‐ sowie als Photokatalysator zur effizienten Bildung von Wasserstoff verwendet werden.

An Efficient RuII–RhIII–RuII Polypyridyl Photocatalyst for Visible‐Light‐Driven Hydrogen Production in Aqueous Solution

“…Until now, none of these photocatalysts has operated efficiently in pure aqueous solution: a highly desirable medium for energy-conversion applications. [12,[19][20][21][22][23] In some cases, TONs of 1000 or more have been reached, generally by using a low concentration of the catalyst in combination with a high PS/HEC ratio. This study also demonstrates unambiguously that the catalytic performance of such systems linked through a nonconjugated bridge is significantly improved as compared to that of a mixture of the separate components.…”

“…Herein, we introduce a new ruthenium-rhodium polypyridyl complex as the first efficient homogeneous photocatalyst for H 2 production in water with turnover numbers of several hundred. [17,[19][20][21]23] Besides the development of such multicomponent systems, more recently, various single-component photocatalysts have been designed by coupling the PS and the HEC in the same molecule through a bridging ligand. [1,2] Since the end of the 1970s, considerable effort has been devoted to the development of multicomponent homogeneous molecular systems for photocatalytic H 2 evolution that consist of a light-harvesting antenna (photosensitizer, PS), a hydrogen-evolving catalyst (HEC), and a sacrificial electron donor coupled or not to an electron mediator.…”

“…[3][4][5][6][7][8] However, systems operating in pure aqueous solution-a highly desirable medium for their subsequent application in photoelectrochemical watersplitting devices [9][10][11][12][13] -remain only moderately developed. [12,[19][20][21][22][23] In some cases, TONs of 1000 or more have been reached, generally by using a low concentration of the catalyst in combination with a high PS/HEC ratio. [12,[19][20][21][22][23] In some cases, TONs of 1000 or more have been reached, generally by using a low concentration of the catalyst in combination with a high PS/HEC ratio.…”

“…Among them, efficient molecular systems with a turnover number versus catalyst (denoted TON) above 100 have been obtained with catalysts based on rhodium, [14][15][16][17] platinum, [18] and cobalt complexes. [17,[19][20][21]23] Besides the development of such multicomponent systems, more recently, various single-component photocatalysts have been designed by coupling the PS and the HEC in the same molecule through a bridging ligand. [17,[19][20][21]23] Besides the development of such multicomponent systems, more recently, various single-component photocatalysts have been designed by coupling the PS and the HEC in the same molecule through a bridging ligand.…”

Electrocatalytic Hydrogen Production with a Molecular Cobalt Complex in Aqueous Solution

“…Zhao et al. utilized a cobalt complex with four pyridine and one amine donors in neutral water with a mercury electrode . Both complexes were active at potentials close to the Co II|I potentials.…”