A series of silica-supported lanthanide (yttrium, lanthanum, neodymium and samarium) silylamides have been prepared using supports dehydroxylated at 250, 500 and 700°C. According to the silica dehydroxylation temperature, different surface species distributions were obtained. These solids, under proper conditions, polymerise methylmethacrylate, ethylene, e-caprolactone and isoprene. In the case of methylmethacrylate, structure-activity and -selectivity relationships for the surface species could be determined, while in the case of ethylene, no such information could be deduced, even if strong support effect was observed. These materials are also active in homocoupling of benzaldehyde to benzylbenzoate (Tischenko reaction) and in dimerisation of 1-heptyne into enyne. In these latter two cases, recycling of the catalytic system was successful.