Catalytic Properties of Ni3Al Foils for Methanol Decomposition

Abstract

Hydrogen was produced by methanol decomposition over cold-rolled foils of intermetallic compound Ni 3 Al which is known as an excellent high-temperature structural material. We found high catalytic activity and selectivity for methanol decomposition in flat cold-rolled Ni 3 Al foils. The catalytic activity was enhanced above 713 K by the spontaneous formation of fine Ni particles dispersed on carbon nanofibers during the reaction, resulting in high catalytic performance. The results demonstrate that the Ni 3 Al foils can be used both as catalyst precursors and as structural materials of microreactors for hydrogen production.

Catalytic Activity of Ni₃Al Foils in Methanol Reforming

“…An increase in the water content in the mixture improves the conversion. Small amounts of water (~5%) result in a small improvement in the methanol decomposition -the process begins earlier and reaches a level of 98% at temperatures above 430 O C. This is in contrast to the recent literature, where a comparable level of conversion (98%) [5,6] was obtained at a higher temperature -about 520 O C -for 29 hours. At temperatures similar to those used in our experiment (about 440 O C), the authors of the above-cited literature obtained less than 80% methanol conversion for 65 hours.…”

“…Another method for obtaining thin foils (with microcrystalline structures only) was reported by Hirano et al [4], where directionally solidified ingots were rolled at room temperature. For materials obtained according to this method, the authors confirmed good catalytic properties in methanol decomposition [5,6].…”

“…4). For both cases of material structures, we obtained carbon nanofibres much smaller than those reported in the literature [5,6]. The metal-like nanoparticles were found to be nanoparticles of pure nickel built in a carbon nanofibre structure.…”

“…Methanol is expected to be used as an alternative energy source (as a fuel) in the near future because it can be synthesized from biomass, natural gas, coal, etc., which are more abundant than crude oil [6][7][8]. Additionally, methanol decomposition to hydrogen and carbon monoxide is an endothermic process, and therefore, it allows for the possibility of recovering waste heat from industrial and automobile exhaust gases.…”

“…The main aim of this work is to investigate the influence of Ni 3 Al foil structures (nano and microstructures) on methanol decomposition and to further verify the catalytic activity of materials obtained by author's method [2,3], which differs from that described in the present literature [5,6]. …”