Development of Nanostructured Materials for Fuel Cells Electrocatalyst Support and Supercapacitor Electrode

Fuel cells and supercapacitors emerge in the recent few years in response to the needs for clean and sustainable energy supplying devices. These two devices use carbon for their core components. In addition to its prominent electrical properties, carbon is economical and abundant in stock. It is therefore understandable that carbon is currently the most popular electrocatalyst support and supercapacitors electrode material. The popularity of carbon makes the development of carbon an old yet still hot research topic. Nowadays, it is focused on the nanostructuration and functionalization for a high performance electrochemical energy supplying devices. We were working on this particular subject, using spray pyrolysis to synthesize macroporous nitrogen-functionalized carbon particles from melamine resin. Formation of the macropores relied on the utilizaAditya Farhan ARIF

Fuel cells and supercapacitors emerge in the recent few years in response to the needs for clean and sustainable energy supplying devices. These two devices use carbon for their core components. In addition to its prominent electrical properties, carbon is economical and abundant in stock. It is therefore understandable that carbon is currently the most popular electrocatalyst support and super-capacitors electrode material.
The popularity of carbon makes the development of carbon an old yet still hot research topic. Nowadays, it is focused on the nanostructuration and functionalization for a high performance electrochemical energy supplying devices. We were working on this particular subject, using spray pyrolysis to synthesize macroporous nitrogen-functionalized carbon particles from melamine resin.
Formation of the macropores relied on the utiliza-Aditya Farhan ARIF

Young Researcher Scholarship Report
-175 -tion of polystyrene latex (PSL) as the sacrificial template. PSL decomposed in the middle of the pyrolysis process, i.e. at approximately 400°C. Droplets were generated by ultrasonic nebulizer and nitrogen was used as carrier gas. Droplets containing melamine resin and PSL underwent thermal decomposition in a tubular furnace of which temperatures were divided into five stacks, i.e. 200, 400, 800, 1000, and 1000°C. The rapid thermal decomposition allowed preservation of the nitrogen in the precursor, that microporous carbon particles with a nitrogen content of 5.44% were obtained at the end of the synthesis. The pore size is controllable, depending on the size of PSL, as seen in Figure 1. The optimum porous structure was obtained using a PSL to melamine resin mass ratio of 1.6 : 1 using 270 nm PSL as template (Figure 1 (c)).
Although we have successfully synthesized nanostructured and functionalized carbon particles which are potential to be used as electrocatalyst support and supercapacitors electrode, we realized the cyclic stability issue when using carbon in some electrochemical devices. Based on this concern, another material intended as a replacement for carbon was further developed.
The material is called Magnéli phase TiO x , or simply TiO x . This is a substoichiometric form of TiO 2 having a chemical formula of Ti n O 2n-1 . TiO x basically has a similar structure with rutile TiO 2 . Due to the oxygen vacancies, the electrons of Ti atoms are shared in some places, forming a shear plane which acts as a good electron conductor. In short, TiO x , especially Ti 4 O 7 , has a high electron conductivity of which value is comparable to that carbon delivers. In recent years, several efforts have been devoted to synthesizing Magnéli phase TiO x , typically by the reduction of rutile titania (TiO 2 ) under high temperatures between 600 and 1000°C. However, the high reduction temperature promotes heavy sintering. In response to this problem, we employed plasma method to synthesize nano-sized TiO x particles from TiO 2 , which we believe to be the first time in the world.
The rapid nucleation inside the plasma reactor induced the formation of small sized particles (approximately 20 nm). The electrical resistivity of the synthesized TiO x could be as low as 0.04 Ω.cm. Electrochemical characterization of the nanoparticles shows remarkable stability of TiO x nanoparticles in a strongly oxidizing environment (1 M HCl, oxygen saturated).