A nanocatalyst, dual catalyst and methods for improving the efficiency and output of a biomass gasification process are provided where the catalysts comprise a volatile organometallic compound(s) and/or a nanoalloy catalyst. By the catalyst and method, a very high biomass gasification conversion efficiency of over 85% can be achieved. The subject nanocatalyst cracks and gasifies lignin, which is generally inert in conventional gasification, at relatively low gasification temperatures. The subject disclosure also provides a means to increase gas yields and lower lignin content in the resulting product relative to conventional gasification. Alternatively, oil production may be increased, if desired. Moreover, the resulting gas may achieve a Fischer-Tropsch reactor favorable H2:CO ratio of about 9:1. The energy input to the gasification is correspondingly reduced to reduce costs and the environmental impact associated with the gasification process.