The Barrier for CO2 Functionalization to Formate on Hydrogenated Pt
Jan Fingerhut1, Dmitriy Borodin1,2, Michael Schwarzer1
1Institute for Physical Chemistry, Georg-August University of Goettingen, Tammannstraße 6, 37077 Goettingen, Germany.
This study experimentally determined the energy barrier for carbon dioxide (CO2) functionalization on platinum surfaces. The findings reveal that surface steps can lower this barrier, offering insights for catalyst optimization.
Area of Science:
- Surface Chemistry
- Heterogeneous Catalysis
- Chemical Kinetics
Background:
- Understanding catalytic processes requires knowledge of energy landscapes.
- Energetic stability of intermediates and reaction barriers are crucial in heterogeneous catalysis.
Purpose of the Study:
- To experimentally determine the barrier to carbon dioxide (CO2) functionalization into bidentate formate on a platinum (Pt) surface.
- To measure the reaction energy for this process.
- To investigate the effect of surface steps on CO2 functionalization barriers.
Main Methods:
- Utilized velocity-resolved kinetics to simultaneously study reaction dynamics and rates.
- Employed isotopically labeled formic acid (DCOOH) to form bidentate formate (DCO*O*) on a hydrogenated Pt surface.
- Established reaction mechanisms by dosing with oxygen (O2) to form adsorbed O* and observe water formation.
Main Results:
- Determined the activation energy for DCO*O* decomposition, reflecting the transition state energy.
- Derived heat of formation for DCO*O* on Pt(111), consistent with microcalorimetry.
- Showed that surface steps on Pt (e.g., Pt(332) vs. Pt(111)) reduce the CO2 functionalization barrier.
Conclusions:
- Velocity-resolved kinetics provides a method to experimentally determine reaction barriers and energies in heterogeneous catalysis.
- Surface steps on platinum catalysts can significantly lower the activation barrier for CO2 functionalization.
- This approach can guide the optimization of catalysts for CO2 conversion.
More Related Videos
08:40Synthesis of Metal Nanoparticles Supported on Carbon Nanotube with Doped Co and N Atoms and its Catalytic Applications in Hydrogen Production
Published on: December 6, 2021
10:19Synthesis and Testing of Supported Pt-Cu Solid Solution Nanoparticle Catalysts for Propane Dehydrogenation
Published on: July 18, 2017
Related Concept Videos
02:13Reduction of Alkenes: 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...
02:17Reduction of Alkenes: Asymmetric Catalytic Hydrogenation
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...
02:24Reduction of Alkynes to cis-Alkenes: Catalytic Hydrogenation
Like alkenes, alkynes can be reduced to alkanes in the presence of transition metal catalysts such as Pt, Pd, or Ni. The reaction involves two sequential syn additions of hydrogen via a cis-alkene intermediate.
02:47Alkynes to Aldehydes and Ketones: Hydroboration-Oxidation
One of the convenient methods for the preparation of aldehydes and ketones is via hydration of alkynes. Hydroboration-oxidation of alkynes is an indirect hydration reaction in which an alkyne is treated with borane followed by oxidation with alkaline peroxide to form an enol that rapidly converts into an aldehyde or a ketone. Terminal alkynes form aldehydes, whereas internal alkynes give ketones as the final product.
01:28Reduction of Benzene to Cyclohexane: Catalytic Hydrogenation
02:36Regioselectivity and Stereochemistry of Hydroboration
Hydroboration proceeds in a concerted fashion with the attack of borane on the π bond, giving a cyclic four-centered transition state. The –BH2 group is bonded to the less substituted carbon and –H to the more substituted carbon. The concerted nature requires the simultaneous addition of –H and –BH2 across the same face of the alkene giving syn...