Nitrogen-doped biochar-supported metal catalysts: High efficiency in both catalytic transfer hydrogenation of furfural and electrocatalytic oxygen reactions

resumo

The versatility of several N-doped biochar-supported metal catalysts (M/N-BioC) derived from vineyard pruning waste, to promote circular bioeconomy, was evaluated in catalytic transfer hydrogenation (CTH) of furfural (FF), electrocatalytic oxygen reduction and evolution reactions (ORR and OER). The CTH of FF to prepare high valuable chemicals was performed in the presence of formic acid as hydrogen donor at 160 degrees C, reaching high conversion (up to 80 %) and selectivities towards furfuryl alcohol (ca. 88 %), establishing a promising catalytic route to valorise a biomass platform molecule using 3d-transition metal-based catalysts in absence of molecular hydrogen. The prepared materials also demonstrated moderate ORR electrocatalytic performance in alkaline medium with diffusion-limiting current densities between -3.48 (Co/N-BioC) and -1.27 mA cm-2 (Cu/N-BioC) and potential onset values of 0.88 >= Eonset >= 0.66 V vs. RHE. Additionally, the materials tested showed selectivity towards indirect pathway in which O2 is reduced to H2O2 and then further reduced to water with the number of electrons transferred per O2 molecule ranging from 2.1 to 3.6 electrons. The materials also presented moderate OER electrocatalytic performances in alkaline medium, with overpotential values between 0.48 (Co/N-BioC) and 0.63 V vs. RHE (Fe/N-BioC) and maximum current densities between 0.28 (BioC) and 42.60 mA cm-2 (Co/N-BioC). This research contributes to the development of a new type of promising (electro)catalyst based on biomass residue for biomass valorisation and energy conversion as a promising contribute to the future of bio-refineries implementation.

palavras-chave

FORMIC-ACID; NICKEL-CATALYST; IN-SITU; CARBON; REDUCTION; BIOMASS; ALCOHOL; PERFORMANCE; PYROLYSIS; CHEMICALS

categoria

Chemistry; Engineering

autores

Marques, IS; Jarrais, B; Ramos, R; Abdelkader-Fernandez, VK; Yaremchenko, A; Freire, C; Fernandes, DM; Peixoto, AF

Grupos

G3 - Materiais Eletroquímicos, Interfaces e Revestimentos

Projectos

CICECO - Aveiro Institute of Materials (UIDB/50011/2020)

CICECO - Aveiro Institute of Materials (UIDP/50011/2020)

Associated Laboratory CICECO-Aveiro Institute of Materials (LA/P/0006/2020)

agradecimentos

This work was funded by Portuguese funds through Fundacao para a Ciencia e a Tecnologia (FCT/MCTES) in the framework of the project EXPL/BII-BIO/0436/2021. Thanks are also due to FCT for the projects UIDB/50006/2020, UIDP/50006/2020. I.S.M. thanks FCT for her working contract in the framework of Project EXPL/BII-BIO/0436/2021. D.M.F. and A.F.P. thank FCT for funding through the Individual Call to Scientific Employment Stimulus (Refs. 2021.00771. CEECIND/CP1662/CT0007 and 2020.01614. CEECIND/CP1596/CT0007 respec-tively) . VKAF thanks the Junta de Andalucia (Spanish regional government) for his current Postdoc contract (PAIDI 2020, Young Doctors Program) . A.Y. acknowledges financial support by the project CICECO-Aveiro Institute of Materials (UIDB/50011/2020, UIDP/50011/2020 & LA/P/0006/2020) financed by national funds through the FCT/MCTES (PIDDAC) . The authors are grateful to Marta Ferro for experimental assistance with the TEM studies.