Elucidation of the catalyst role during reductive catalytic fractionation, enabling the integration of lignin valorization and bio-ethanol production.

Lignocellulosic biomass is disassembled and depolymerised into three easily separable product streams, derived from lignin, hemicellulose, and cellulose.

growing body of literature recognizes the importance of a sustainable production of fuel (additives) 1-3 , chemicals and materials 4 from abundant and renewable lignocellulose 5,6 . Despite lignocellulose's high degree of functionality 7 , its conversion into alkanes can become an important alternative for bio-enrichment or the replacement of fossil-based alkanes 8 . The synthesis of identical molecules from an alternative biomass feedstock, instead of from crude oil, encompasses a promising strategy for the integration of bio-based carbon in the short term 9 . Integration of these technologies in an existing petrorefinery is, perhaps, the most straightforward and efficient way to proceed, but such synergies are currently immature.In line with rising concerns about fossil-derived CO 2 and climate change, objectives related to the implementation of renewable energy, including biofuels, have been put forward (Supplementary Note 1) 10 . The dependency of our current transportation market on diesel (C 10 -C 22 ), kerosene (C 8 -C 16 ) and gasoline (C 5 -C 12 ), certainly in the short-to-mid term, will still be high 11 . Therefore, the European Union for one, has targeted a market share of 10% for biofuels in transportation by 2020 12 , with a maximum of 7% from first-generation biomass 10 . Introducing renewable diesel as a dropin fuel, for instance, by Neste Oil, is one example to achieve these objectives. Nevertheless, the consumption of diesel, in contrast to that of gasoline, leads to a higher emission of particulate matter and NO x (for example, diesel exhaust emission scandals), a problem not solved by biodiesel replacement. Therefore, the importance of light fuels, such as gasoline, whether or not as an energy carrier in a future hybrid engine, will probably increase. Currently, gasoline, which is synthesized by blending different petrorefinery streams (for example, alkylate, isomerate and reformate) and light distillate feedstock, has an annual consumption of approximately 32 vol% of

In the valorization of α-pinene, which is an important biomass intermediate derived from turpentine oil, hierarchical (mesoporous) zeolites represent a superior class of catalysts. Hierarchical USY, ZSM-5, and beta zeolites have been prepared, characterized, and catalytically evaluated, with the aim of combining the highest catalytic performance with the most sustainable synthetic protocol. These zeolites are prepared by alkaline treatment in aqueous solutions of NH4 OH, NaOH, diethylamine, and NaOH complemented with tetrapropylammonium bromide. The hierarchical USY zeolite is the most attractive catalyst of the tested series, and is able to combine an overall organic-free synthesis with an up to sixfold activity enhancement and comparable selectivity over the conventional USY zeolite. This superior performance relates to a threefold greater activity than that of the commercial standard, namely, H2 SO4 /TiO2 . Correlation of the obtained benefits to the amount of solid lost during the postsynthetic modifications highlights that the highest activity gains are obtained with minor leaching. Furthermore, a highly zeolitic character, as determined by bulk XRD, is beneficial, but not crucial, in the conversion of α-pinene. The alkaline treatments not only result in a higher overall activity, but also a more functional external surface area, attaining up to four times the pinene conversions per square nanometer. The efficiency of the hierarchical USY zeolite is concomitantly demonstrated in the conversion of limonene and turpentine oil, which emphasizes its industrial potential.

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