Boudouard reaction under graphene cover

Title : Boudouard reaction under graphene cover

Abstract:

Ni is known to be a catalyst for the Boudouad reaction

CO+CO ® CO₂ + C

This reaction is favoured by high pressure and it thus escaped so far direct investigation under operando conditions.  We report here about a Near Ambient Pressure XPS study performed at Soleil (Tempo Beamline).

Exposing bare Ni(111) to CO at a pressure P_CO∼2 mbar we observed indeed graphene growth already at 550 K [1], a temperature significantly lower than the one (670 K) at which  growth of graphene by segregation of dissolved carbon occurs.

It was recently shown [2]  that  the space between graphene and the substrate can act as a nano-reactor where the activation barrier for CO oxidation is effectively reduced. We show here that this is the case also for the Boudouard reaction.

Exposing single layer  Graphene on Ni(111) to CO at 3.7 mbar, CO intercalates under the graphene layer causing its detachment from the substrate. The so obtained high local CO coverage under graphene cover enables the formation of CO₂ via the Boudouard reaction catalysed by the Ni(111) surface already at 340 K. The carbon produced by the reaction is used to transform carbide into graphene. Moreover under such conditions a chemisorbed CO species above graphene is observed, thus paving the use of graphene as an active support in catalysis.

Audience take-away:

• Brief overview about chemistry under graphene cover
• Near Ambient pressure XPS study of the Boudouard reaction
• Growth of graphene by the Boudouard reaction using Ni as catalyst
• Graphene as an active support for catalysis

Biography:

L.V. got his PhD from the university of Genoa. After a post-doctoral position at the University of Cambridge (UK) he came back to Genoa firstly as a post-doc and then as an Assistant Professor (1999). In 2012 he became Associate Professor of Condensed Matter Physics. His research activity focused on experimental investigation of gas-surface interaction using vibrational spectroscopy, photoemission, supersonic molecular beams and calorimetry. He also investigated surface plasmon dispersion.  He published to date 135 papers and is a member of the Editorial Board of Coatings and of 4 Open