Flame spray pyrolysis (FSP) was applied to produce nanopowders of Ti1-xMxO2 and Sn1-xMxO2, where x = 0.05 and M = Nb/Sb, for use as catalyst support materials in PEM fuel cells/ electrolysers. FSP powders in the SnO2-IrO2 system were produced for the same applications. Homogenous particle size distribution (5-20 nm) was demonstrated by TEM, supported by BET and XRD analysis. Whereas two polymorphs were indicated for the Ti-based oxides, the Sb/Nb-doped SnO2 powders were single phase. FSP powders of Mn3O4 intended for supercapacitors were produced and the influence of the precursor/solvent mixtures on the physical and electrochemical properties evaluated.