Dataset Information

How Rh surface breaks CO₂ molecules under ambient pressure.

ABSTRACT: Utilization of carbon dioxide (CO₂) molecules leads to increased interest in the sustainable synthesis of methane (CH₄) or methanol (CH₃OH). The representative reaction intermediate consisting of a carbonyl or formate group determines yields of the fuel source during catalytic reactions. However, their selective initial surface reaction processes have been assumed without a fundamental understanding at the molecular level. Here, we report direct observations of spontaneous CO₂ dissociation over the model rhodium (Rh) catalyst at 0.1 mbar CO₂. The linear geometry of CO₂ gas molecules turns into a chemically active bent-structure at the interface, which allows non-uniform charge transfers between chemisorbed CO₂ and surface Rh atoms. By combining scanning tunneling microscopy, X-ray photoelectron spectroscopy at near-ambient pressure, and computational calculations, we reveal strong evidence for chemical bond cleavage of O?CO* with ordered intermediates structure formation of (2?×?2)-CO on an atomically flat Rh(111) surface at room temperature.

SUBMITTER: Kim J

PROVIDER: S-EPMC7648795 | biostudies-literature | 2020 Nov

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

How Rh surface breaks CO2 molecules under ambient pressure.

Kim Jeongjin J Ha Hyunwoo H Doh Won Hui WH Ueda Kohei K Mase Kazuhiko K Kondoh Hiroshi H Mun Bongjin Simon BS Kim Hyun You HY Park Jeong Young JY

Nature communications 20201106 1

Utilization of carbon dioxide (CO2) molecules leads to increased interest in the sustainable synthesis of methane (CH4) or methanol (CH3OH). The representative reaction intermediate consisting of a carbonyl or formate group determines yields of the fuel source during catalytic reactions. However, their selective initial surface reaction processes have been assumed without a fundamental understanding at the molecular level. Here, we report direct observations of s ...[more]

PMID: 33159056

Similar Datasets

Project description:BackgroundReplacing fossil fuels as energy carrier requires alternatives that combine sustainable production, high volumetric energy density, easy and fast refueling for mobile applications, and preferably low risk of hazard. Molecular hydrogen (H2) has been considered as promising alternative; however, practical application is struggling because of the low volumetric energy density and the explosion hazard when stored in large amounts. One way to overcome these limitations is the transient conversion of H2 into other chemicals with increased volumetric energy density and lower risk hazard, for example so-called liquid organic hydrogen carriers such as formic acid/formate that is obtained by hydrogenation of CO2. Many homogenous and heterogenous chemical catalysts have been described in the past years, however, often requiring high pressures and temperatures. Recently, the first biocatalyst for this reaction has been described opening the route to a biotechnological alternative for this conversion.ResultsThe hydrogen-dependent CO2 reductase (HDCR) is a highly active biocatalyst for storing H2 in the form of formic acid/formate by reversibly catalyzing the hydrogenation of CO2. We report the identification, isolation, and characterization of the first thermostable HDCR operating at temperatures up to 70 °C. The enzyme was isolated from the thermophilic acetogenic bacterium Thermoanaerobacter kivui and displays exceptionally high activities in both reaction directions, substantially exceeding known chemical catalysts. CO2 hydrogenation is catalyzed at mild conditions with a turnover frequency of 9,556,000 h-1 (specific activity of 900 µmol formate min-1 mg-1) and the reverse reaction, H2 + CO2 release from formate, is catalyzed with a turnover frequency of 9,892,000 h-1 (930 µmol H2 min-1 mg-1). The HDCR of T. kivui consists of a [FeFe] hydrogenase subunit putatively coupled to a tungsten-dependent CO2 reductase/formate dehydrogenase subunit by an array of iron-sulfur clusters.ConclusionsThe discovery of the first thermostable HDCR provides a promising biological alternative for a chemically challenging reaction and might serve as model for the better understanding of catalysts able to efficiently reduce CO2. The catalytic activity for reversible CO2 hydrogenation of this enzyme is the highest activity known for bio- and chemical catalysts and requiring only ambient temperatures and pressures. The thermostability provides more flexibility regarding the process parameters for a biotechnological application.

Dataset Information

How Rh surface breaks CO₂ molecules under ambient pressure.

Publications

How Rh surface breaks CO<sub>2</sub> molecules under ambient pressure.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets