N‐Doped Defective Graphene from Biomass as Catalyst for CO2 Hydrogenation to Methane

[EN] N-doped, defective graphene obtained by pyrolysis of chitosan at 900 degrees C under Ar exhibits catalytic activity for the Sabatier hydrogenation of CO2 to CH4 at temperatures about 500 degrees C with estimated turnover frequencies and activation energy values of 73.17s(-1) and 24.3 kcal x mol(-1), respectively. It has been found that this enhanced catalytic activity compared to other related doped defective graphenes derives from the presence of pyridinic N atoms that adsorbs CO2 forming carbamate-type adsorbates.
Financial support by the Spanish Ministry of Economy and Competitiveness (Severo Ochoa, Grapas and CTQ2015-69153-CO2-R1) and Generalitat Valenciana (Prometeo 2017-083) is gratefully acknowledged. A.P. thanks the Spanish Ministry for a Ramon y Cajal research associate contract. V.I.P. kindly acknowledges UEFISCDI for financial support (projects PN-III-P4-ID-PCE-2016-0146, Nr. 121/2017, PN-III-P4-ID-PCCF-2016-0088 and PN-III-P1-1.2-PCCDI-2017-0541). Cristina Bucur thanks IFTM for the financial support.