Titania-Carbon Nitride Interfaces in Gold-Catalyzed CO Oxidation
Pablo Jiménez-Calvo1, Loïc Michel1, Valérie Keller1
1ICPEES (Institut de Chimie et Procédés pour l'Energie, l'Environnement et la Santé), University of Strasbourg/CNRS UMR 7515, 25 rue Becquerel, 67087 Strasbourg Cedex 02, France.
Gold catalysts show tunable porosity for CO oxidation. Composites with titania nanotubes enable hydrogen-mediated pathways, crucial for preferential CO oxidation (PROX) over large pores.
Area of Science:
- Materials Science
- Catalysis
- Surface Chemistry
Background:
- Gold catalysis for CO oxidation is vital, with oxygen activation pathways influenced by catalyst support chemistry.
- Titania supports yield active catalysts, while carbon nitride supports result in inactive ones for CO oxidation.
Purpose of the Study:
- To engineer C3N4-TiO2 composite catalysts with tunable mesoporosity for CO oxidation.
- To investigate the impact of support surface chemistry and porosity on dry CO oxidation and preferential CO oxidation (PROX).
Main Methods:
- Synthesis of C3N4-TiO2 composites using titania nanotubes as hard templates.
- Tuning mesoporosity (8-40 nm) by varying C3N4 content (2-75 wt %).
- Loading well-calibrated 2-4 nm gold nanoparticles and evaluating catalytic activity for CO oxidation and PROX.
Main Results:
- Support surface chemistry has less impact on PROX than dry CO oxidation.
- NH2-terminated and OH-terminated supports exhibit similar activity in PROX.
- Hydrogen/water-mediated CO oxidation pathways are active on C3N4-based Au catalysts.
- PROX activity correlates with large mesoporosity (40 nm), suggesting larger reaction intermediates.
Conclusions:
- Engineered C3N4-TiO2 composites offer tunable porosity for enhanced catalytic performance.
- PROX reactions on these materials likely involve hydrogen/water mediation and larger intermediates, differing from dry CO oxidation mechanisms.
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
10:57Synthesis and Performance Characterizations of Transition Metal Single Atom Catalyst for Electrochemical CO2 Reduction
Published on: April 10, 2018
Related Concept Videos
02:50Catalysis
02:44Oxidation of Alkenes: Syn Dihydroxylation with Osmium Tetraoxide
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.
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...