Green catalysts and catalytic processes for biofuel production

Global population growth and rapid urbanization drive the quest for alternative, sustainable energy sources, especially for the transportation sector, which alone contributed to 21% of worldwide anthropogenic CO2 emissions from fossil fuels in 2013. The natural abundance and potential carbon neutrality of plant and algal biomass render it ideal feedstocks for production of sustainable liquid transportation fuels. A variety of catalytic technologies have been developed for the energy efficient conversion of lignocellulosic biomass to bio-derived fuels and chemicals. Here we review a range of such heterogeneously catalyzed processes, including esterification, transesterification, Fischer-Tropsch synthesis and hydrodeoxygenation, and associated inorganic nanocatalysts, for transformation of lignin, carbohydrate and oil feedstocks. Design of robust catalytic materials, with mass transport properties tailored for the rapid diffusion of bulky molecules, high selectivity and minimal deactivation, is a particular focus of discussions.