If the sodium hydroxide is insufficiently concentrated then ‘bayerite’ can form. Find its chemical formula and suggest what problems this could pose for the catalyst.
Even though the aluminium in the catalyst is chemically bound to the nickel the reaction proceeds as if the two were separate entities, the nickel being unreactive (and so removed from this equation). The normal reaction of aluminium metal with sodium hydroxide is:
Rather than leaving the positions of the nickel atoms untouched the atoms ‘migrate’ in three dimensions to form a sponge like structure. The bulk volume of the catalytic particles is largely unchanged.
If the sodium hydroxide is insufficiently concentrated then ‘bayerite’ can form. Find its chemical formula and suggest what problems this could pose for the catalyst.
Bayerite has the chemical formula Al(OH)3 and is one of the principal constituents of the aluminium ore, bauxite. Since this is a solid it will form deposits within the partially leached catalytic particles, covering some of the catalytic surface and sealing other sections off entirely by blocking the sponge pores.
