Jornal de Ciência de Materiais e Nanomateriais

Abstrato

Nano-structured catalysts for energetic and environmental applications

Luciana Lisi

A good heterogeneous catalyst should have a structural organization that maximizes the amount of active centers on the surface. The modern heterogeneous catalysis is addressed to more and more performing materials and all recent studies converge on the use of highly dispersed phases to create interaction among catalyst components in the nanometric range to provide new special properties. In particular, the catalyst design is based on dispersion of active metals on supports and/or addition of dopants or promoters affecting the metals performance through the creation of novel nano-structures. The role of dispersion of active metals at nanometric level is analyzed through three different catalytic reactions that fall in the field of energetic and environmental applications. The interaction of active rhodium nano-particles deposited on alumina with phosphorous or lanthanum, determining the activity in dry reforming of methane and the resistance to poisoning is described as first example. The very high dispersion of copper on nanometric CeO2 support providing an outstanding activity of this catalyst coupled to a very good selectivity in the oxidation of CO in H2 rich stream for fuel cells is reported as second case study and, finally, the strongly improved contact between CeO2 nano-particles, dispersed into the pores of a diesel particulate filter and soot produced by diesel engine is reported as special case of a solid-solid catalytic reaction.