P-042

Virginija Ulevičienė1

virginija.uleviciene@ftmc.lt

Daina Upskuvienė1, Aldona Balčiūnaitė1, Galina Dobele2, Aleksandrs Volperts2, Ance Plavniece2, Aivars Zhurinsh2, Loreta Tamašauskaitė-Tamašiūnaitė1, Eugenijus Norkus1

Department of Catalysis, Center for Physical Sciences and Technology (FTMC), Vilnius, Lithuania

Latvian State Institute of Wood Chemistry, Dzerbenes Str. 27, LV-1006 Riga, Latvia

Sustainable transition metal and nitrogen co-doped biomass-derived carbon catalysts for oxygen reduction reaction

The quest for catalysts that are both sustainable and highly efficient has led to significant exploration of carbon-based materials sourced from biomass. Unlike synthetic carbon sources, these biomass-derived carbons provide a naturally abundant and renewable option, incorporating inherent heteroatoms such as nitrogen, phosphorus, and sulfur. These heteroatoms are essential in improving the catalytic activity and electronic characteristics of the material. Additionally, the doping of transition metals, particularly nickel, cobalt, and copper, further enhances catalytic performance, making these materials highly effective in electrochemical processes.

In this research, we introduce a simple method for the synthesis of transition metal (Ni, Co, Cu) and nitrogen co-doped biomass-based activated carbon catalysts intended for the oxygen reduction reaction (ORR). Activated wood carbon (AWC) was synthesized using alder wood char as a carbon precursor and then co-doped with Ni, Co, or Cu and nitrogen in a single step, and the resulting materials were designated as AWC-Ni-N, AWC-Co-N, and AWC-Cu-N. The catalysts were extensively analyzed using techniques such as ICP-OES, XRD, XPS, SEM-EDS, BET surface area analysis, and Raman spectroscopy to assess their elemental composition, structural features, and surface properties. The AWC-Ni-N catalyst contained 1.12 at.% Ni and 98.88 at.% C, the AWC-Co-N catalyst had 1.29 at.% Co and 98.71 at.% C, while the AWC-Cu-N catalyst contained 1.19 at.% Cu and 98.81 at.% C.

The ORR performance of AWC-N, AWC-Ni-N, AWC-Co-N, and AWC-Cu-N catalysts was studied by cyclic voltammetry (CV) in an Ar- or O2-saturated 0.1 M KOH solution, with electrode potentials ranging from 0.2 to -0.8 V (vs. SCE) at a scan rate of 10 mV s⁻¹. 

A more distinct oxygen reduction peak was observed for the all AWC-Ni-N, AWC-Co-N, and AWC-Cu-N catalysts compared to AWC-N, signifying that the incorporation of Ni, Co, or Cu enhances the catalytic performance. The onset potential, or the potential at which the ORR is initiated, was notably more positive for AWC-Ni-N, AWC-Co-N, and AWC-Cu-N than for AWC-N, indicating that these catalysts require a lower overpotential to initiate the reaction, and thus exhibit superior catalytic efficiency. Furthermore, the AWC-Ni-N, AWC-Co-N, and AWC-Cu-N catalysts demonstrated good stability for the oxygen reduction reaction, highlighting their potential as effective electrode materials for sustainable fuel cell applications.