Three main research objectives form the basis of the work described in this thesis: i) preparation of highly active and selective supported V-P-O catalysts for the selective oxidation of n-butane to maleic anhydride; ii) characterisation of the structure of the supported V-P-O catalysts and determination of the nature of the active sites and iii) determination of the mechanism of the oxidation reaction. This final chapter deals with a summary of the results described in the preceding chapters of this thesis. Suggestions for further research in this field will be proposed