Introduction.
An important reaction contributing to the development of hydrogen energy and the potential replacement of the Haber–Bosch industrial process for ammonia synthesis is the electrocatalytic nitrogen reduction reaction, as well as the key reactions for optimizing this latter reaction: electrocatalytic nitrate and nitrite reduction reactions. Due to nitrate contamination of agricultural and industrial wastewater, nitrite contamination can be more dangerous due to the greater toxicity of the nitrite ion. Thus, the search for efficient and low-cost catalysts based on non-precious metals and their compositions is currently crucial. In turn, intermetallic compounds (IMCs) are currently poorly studied for this purpose and, at the same time, are in demand, since their catalytic efficiency can potentially approach single atomic catalysts (SACs). The aim of our study is to synthesize IMCs based on Ge and transition metals and test catalysts based on this in the electrochemical nitrite reduction reaction (NO2–RR).
Methods.
The Ge-IMC samples were prepared using arc melting in an argon atmosphere at the AM-200 facility. Mass control of the samples after fusion showed that melting losses did not exceed 1 mass%. The physicochemical methods of characterization of Ge-IMC samples were used in the work: UV-vis spectroscopy and XRD. Linear voltammetry and chronoamperometry were used to determine the optimal conditions for the reactions and synthesis of ammonia, respectively. Autolab PGSTAT302N and PS-20 potentiostats were also used.
Results and Discussion.
The results show that the use of Ge electrocatalysts is promising, since excellent values of Faradaic efficiency (FE) and ammonia yield rate were achieved in the NO2–RR . Moreover, IMC-based catalysts showed good results at significantly lower potentials than solid solution catalysts.
Acknowledgment.
The research was carried out at the expense of the grant of Russian Science Foundation (RSF) No 25-29-00488, https://rscf.ru/en/project/25-29-00488/.
