@article{schmal_freund_2009,  title={Towards an atomic level understanding of niobia based catalysts and catalysis by combining the science of catalysis with surface science},  volume={81},  ISSN={0001-3765},  url={https://doi.org/10.1590/S0001-37652009000200016},  DOI={10.1590/S0001-37652009000200016},  number={2},  journal={Anais da Academia Brasileira de Ciências},  publisher={Academia Brasileira de Ciências},  author={Schmal, Martin and Freund, Hans-Joachim},  year={2009},  month={Jun},  pages={297–318} }