In situ formation of Ni nanoparticles inside a Si-C-N-O(H) ceramic obtained via the PDC route : Possible application for OER
BEN MILED M. 1,2, CÉLÉRIER S. 2, HABRIOUX A. 2, MASSON O. 1, BERNARD S. 1
1 IRCER, Limoges, France; 2 IC2MP, Poitiers, France
Hydrogen is considered as a promising energy carrier to assure the needs of humanity. Its combustion in a fuel cell (FC) emits only water and does not involve any noise pollution. The use of H2 in a fuel cell requires it to be obtained at a very high level of purity, which can be easily achieved by water electrolysis. This process i) uses noble metal catalysts that are difficult to substitute in the PEM technologies that are currently the most mature for low temperature electrolysis, ii) has limited electrical performance due to anode overpotential. The recent development of anion exchange membrane materials has led to the emergence of a new technology: the anion exchange membrane electrolyser. This device allows the use of non-noble transition metals in the composition of catalysts for hydrogen (HER) and oxygen (OER) evolution reactions in alkaline media. However, their nanoscaled synthesis is highly challenging to limit the overpotential, particularly at the anode (OER); one of the half-reaction of water electrolysis involving a four-electron transfer hampered by kinetic factors.
The PDC (Polymer Derived Ceramics) route is a way to generate ceramics from pre-ceramic polymers used as precursors. Organosilicon polymers are usually used as pre-ceramic polymers. Their backbone represents a highly reactive platform to link or coordinate lower-molecular weight TM complexes. Thus, the as-obtained pre-ceramic polymer will promote upon heat-treatment, in general at low temperature, the precipitation of well dispersed transition metal nanoparticles in an amorphous Si-C-O-N ceramic because of the strong reducing properties of organosilicon polymers. Having in mind that pre-ceramic polymers display an intrinsic ability to form micropores in the low-temperature regime of the thermolysis, the resulting nanocomposites produced at low temperature are expected to : (i) display long-term stability due to stronger nanoparticle-matrix interaction and high corrosion resistance of the matrix; (ii) expose and access more active sites ; (iii) avoid active sites aggregation during electrochemical process leading thereby to a constant catalytic activity; and (iv) have practical applicability. This oral communication will discuss on recent works obtained in the framework of the SYNERGY project between IRCER and IC2MP. They are based on the implementation of the PDC route to in situ form Ni nanoparticles in an amorphous Si-C-N-O(H) ceramic support at low temperatures (300-700 °C). The large specific surface area of the materials associated with the nanometric size (20-50 nm) of the Ni particles made it possible to boost OER performances, which suggests very promising prospects for the development of anion exchange membrane electrolysers .
 R. K. M. Ferreira, M. Ben Miled, R. K. Nishihora, N. Christophe, P. Carles, G. Motz, A. Bouzid, R. Machado, O. Masson, Y. Iwamoto, S. Célérier, A. Habrioux, S. Bernard, accepted in Nanoscale. Adv., 2023