Because n‐butanol as a fuel additive has more advantageous physicochemical properties than those of ethanol, ethanol valorization to n‐butanol through homo‐ or heterogeneous catalysis has received much attention in recent decades in both scientific and industrial fields. Recent progress in catalyst development for upgrading ethanol to n‐butanol, which involves homogeneous catalysts, such as iridium and ruthenium complexes, and heterogeneous catalysts, including metal oxides, hydroxyapatite (HAP), and, in particular, supported metal catalysts, is reviewed herein. The structure–activity relationships of catalysts and underlying reaction mechanisms are critically examined, and future research directions on the design and improvement of catalysts are also proposed.

catalyst exhibited 49.8% of ethanol conversion, 48.6% of selectivity toward n-butanol, and thereby 24.2% of n-butanol yield at relatively low temperature (523 K) and pressure (2 MPa) during a 200 h long-term evaluation. The high catalytic activity and selectivity of Pd@UiO-66 catalyst are primarily ascribed to the close synergy of highly dispersed Pd nanoparticles and coordinatively unsaturated Zr sites on Zr 6 nodes of UiO-66, as active centers for dehydrogenation/hydrogenation and aldol condensation, respectively; however, the high stability of the catalyst is mainly attributed to the electrostatic attraction of Pd nanoparticles with Zr 6 nodes and the confinement effect of the cavities of UiO-66.

Cu-CeO/AC catalysts exhibited extraordinary catalytic performance in the upgradation of ethanol to n-butanol. To the best of our knowledge, this is the first report that the highest n-butanol yields of 21.6% and nearly 20% could be achieved over heterogeneous catalysts under mild reaction conditions in batch and fixed-bed reactors, respectively. The high catalytic activity, selectivity and stability of these catalysts could be ascribed to the synergy of Cu, CeO and the activated carbon support.

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Polyethylene terephthalate is one of the most abundantly used polymers, but also a significant pollutant in oceans. Due to growing environmental concerns, polyethylene terephthalate alternatives are highly sought after. Here we present readily recyclable polyethylene terephthalate analogues, made entirely from woody biomass. Central to the concept is a two-step noble metal free catalytic sequence (Cu20-PMO catalyzed reductive catalytic fractionation and Raney Ni mediated catalytic funneling) that allows for obtaining a single aliphatic diol 4-(3-hydroxypropyl) cyclohexan-1-ol in high isolated yield (11.7 wt% on lignin basis), as well as other product streams that are converted to fuels, achieving a total carbon yield of 29.5%. The diol 4-(3-hydroxypropyl) cyclohexan-1-ol is co-polymerized with methyl esters of terephthalic acid and furan dicarboxylic acid, both of which can be derived from the cellulose residues, to obtain polyesters with competitive Mw and thermal properties (Tg of 70–90 °C). The polymers show excellent chemical recyclability in methanol and are thus promising candidates for the circular economy.