Related Experiment Video
Updated: Jul 26, 2025
10:21
Developing Photosensitizer-Cobaloxime Hybrids for Solar-Driven H2 Production in Aqueous Aerobic Conditions
Published on: October 5, 2019
8.4K
Light-Driven Hydrogen Evolution Reaction Catalyzed by a Molybdenum-Copper Artificial Hydrogenase
Raphaël J Labidi1, Bruno Faivre1, Philippe Carpentier2
1Laboratoire de Chimie des Processus Biologiques, UMR 8229, Collège de France/CNRS/Sorbonne Université, 11 place Marcellin-Berthelot, 75231 Paris, France.
Journal of the American Chemical Society
|June 12, 2023
Summary
Orange protein (Orp) with a unique molybdenum/copper cluster catalyzes hydrogen production from protons. Modified Orp variants, especially Mo/Fe-Orp, show record-breaking efficiency as artificial hydrogenases under visible light.
Area of Science:
- Biochemistry
- Bioinorganic Chemistry
- Photocatalysis
Background:
- Orange protein (Orp) is a bacterial metalloprotein with a unique heterometallic cluster of unknown function.
- Metalloproteins offer potential for novel catalytic applications due to their intricate active sites.
Purpose of the Study:
- To investigate the photocatalytic activity of Orange protein (Orp) for hydrogen evolution.
- To characterize the molybdenum/copper (Mo/Cu) heterometallic cluster within Orp and explore its catalytic mechanism.
- To engineer and evaluate modified Orp variants for enhanced hydrogen production.
Main Methods:
- Biochemical and spectroscopic characterization of holo-Orp.
- Docking and molecular dynamics simulations to identify the active site.
- Photocatalytic hydrogen evolution experiments using ascorbate and a photosensitizer.
- Density functional theory (DFT) calculations to elucidate the reaction mechanism.
- Assembly and testing of various dinuclear metal clusters (M/M'-Orp) within the Orp scaffold.
Main Results:
- Holo-Orp containing the [S2MoS2CuS2MoS2]3- cluster demonstrated significant photocatalytic activity for hydrogen evolution.
- A maximum turnover number (TON) of 890 was achieved with holo-Orp after 4 hours of irradiation.
- DFT calculations proposed a mechanism involving terminal sulfur atoms in H2 formation.
- Engineered Mo/Fe-Orp variants exhibited a remarkable TON of 1150 and an initial turnover frequency (TOF°) of 800 h-1, setting a new record for artificial hydrogenases.
Conclusions:
- Orange protein (Orp) is an effective photocatalyst for hydrogen evolution.
- The unique Mo/Cu cluster and specific amino acid residues in Orp are crucial for its catalytic activity.
- Engineered Orp variants, particularly Mo/Fe-Orp, represent highly efficient artificial hydrogenases with potential for sustainable hydrogen production.
Related Concept Videos
02:13Reduction of Alkenes: Catalytic Hydrogenation
12.2K
Alkenes undergo reduction by the addition of molecular hydrogen to give alkanes. Because the process generally occurs in the presence of a transition-metal catalyst, the reaction is called catalytic hydrogenation.
Metals like palladium, platinum, and nickel are commonly used in their solid forms — fine powder on an inert surface. As these catalysts remain insoluble in the reaction mixture, they are referred to as heterogeneous catalysts.
The hydrogenation process takes place on the...
Metals like palladium, platinum, and nickel are commonly used in their solid forms — fine powder on an inert surface. As these catalysts remain insoluble in the reaction mixture, they are referred to as heterogeneous catalysts.
The hydrogenation process takes place on the...
12.2K
02:17Reduction of Alkenes: Asymmetric Catalytic Hydrogenation
3.4K
Catalytic hydrogenation of alkenes is a transition-metal catalyzed reduction of the double bond using molecular hydrogen to give alkanes. The mode of hydrogen addition follows syn stereochemistry.
The metal catalyst used can be either heterogeneous or homogeneous. When hydrogenation of an alkene generates a chiral center, a pair of enantiomeric products is expected to form. However, an enantiomeric excess of one of the products can be facilitated using an enantioselective reaction or an...
The metal catalyst used can be either heterogeneous or homogeneous. When hydrogenation of an alkene generates a chiral center, a pair of enantiomeric products is expected to form. However, an enantiomeric excess of one of the products can be facilitated using an enantioselective reaction or an...
3.4K
02:50Catalysis
27.1K
The presence of a catalyst affects the rate of a chemical reaction. A catalyst is a substance that can increase the reaction rate without being consumed during the process. A basic comprehension of a catalysts’ role during chemical reactions can be understood from the concept of reaction mechanisms and energy diagrams.
27.1K
00:26Hydrogen Bonds
121.5K
Hydrogen bonds are weak attractions between atoms that have formed other chemical bonds. One of these atoms is electronegative, like oxygen, and has a partial negative charge. The other is a hydrogen atom that has bonded with another electronegative atom and has a partial positive charge.
Hydrogen Bonds Control the World!
Because hydrogen has very weak electronegativity when it binds with a strongly electronegative atom, such as oxygen or nitrogen, electrons in the bond are unequally shared....
Hydrogen Bonds Control the World!
Because hydrogen has very weak electronegativity when it binds with a strongly electronegative atom, such as oxygen or nitrogen, electrons in the bond are unequally shared....
121.5K
01:32Chemiosmosis
100.1K
Oxidative phosphorylation is a highly efficient process that generates large amounts of adenosine triphosphate (ATP), the basic unit of energy that drives many cellular processes. Oxidative phosphorylation involves two processes— the electron transport chain and chemiosmosis.
Electron Transport Chain
The electron transport chain involves a series of protein complexes on the inner mitochondrial membrane that undergo a series of redox reactions. At the end of this chain, the electrons...
Electron Transport Chain
The electron transport chain involves a series of protein complexes on the inner mitochondrial membrane that undergo a series of redox reactions. At the end of this chain, the electrons...
100.1K
02:44Oxidation of Alkenes: Syn Dihydroxylation with Osmium Tetraoxide
10.4K
Alkenes are converted to 1,2-diols or glycols through a process called dihydroxylation. It involves the addition of two hydroxyl groups across the double bond with two different stereochemical approaches, namely anti and syn. Dihydroxylation using osmium tetroxide progresses with syn stereochemistry.
10.4K