Towards biofuel combustion with an easily extruded clay as a natural catalyst

► Low-cost natural clay with three forms, powder, pellets and extruded monolith, was tested against biofuel combustion. ► The mineralogical, chemical thermal and textural properties of the clay were characterized. ► The effect of the equivalence ratio and of the total flow rate was investigated. ► The clay proved competitive activity to reactive non-noble transition metal oxides and some coated noble metals. ► The enhanced catalytic activity benefited from the abundance of Fe2O3 combined with some promoters.