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This is the first report of HCl/ZrO(OH)2 catalysts prepared in situ by the autonomous decomposition of ZrOCl2⋅8 H2O in levulinic acid (LA)/2‐butanol solution, which catalyzed the esterification of LA in tandem with hydrocyclization to γ‐valerolactone (GVL) by Meerwein–Ponndorf–Verley (MPV) reduction without the use of external H2. A maximum GVL yield of 92.4 % from neat LA and a GVL formation rate of 1092.2 μmol g−1 min−1 were achieved in 2‐butanol at 240 °C in 2 h. The in situ generated ZrO(OH)2 was characterized comprehensively and its unexpected catalytic efficiency was attributed mainly to its extremely high surface area. A crude LA stream from the acid hydrolysis of cellulose was extracted into 2‐butanol and subjected to this catalyst system to give a GVL yield of 82.0 % even in the presence of humins.

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Constructing a cheap and high-performance catalyst is very important for the selective synthesis of biomass-based 2,5-bis­(hydroxymethyl)­furan (BHMF) from 5-hydroxymethylfurfural via the strategy of catalytic transfer hydrogenation (CTH). Herein, we synthesized a neoteric zirconium–carbon coordination catalyst (Zr-HTC) via a simple self-assembly method, in which glucose-derived hydrothermal carbon (HTC) containing abundant carboxyl and phenolic hydroxyl groups was directly used as a low-cost organic ligand. Satisfyingly, Zr-HTC showed an outstanding catalytic activity for the selective synthesis of BHMF in isopropanol (iPrOH). After 4 h at a mild temperature of 120 °C, 99.2% BHMF yield with 5.61 h–1 turnover frequency (TOF) could be obtained. Detailed experimental results demonstrated that this outstanding catalytic activity of Zr-HTC was mainly contributed by the synergetic effects of Lewis acid–base sites (Zr4+–O2–) with high contents, proper ratios, and strengths under the aid of good hydrophilicity. In addition, Zr-HTC displayed superior catalytic stability, and when it was repeatedly used for five reaction cycles, no noticeable decrease in BHMF yield was found. More significantly, Zr-HTC could also effectively convert a wide range of carbonyl compounds, such as 1-butanal, 1-hexanal, furfural, cyclohexanal, benzaldehyde, phenylacetaldehyde, cyclopentanone, cyclohexanone, levulinic acid, and ethyl levulinate, to the relevant products in iPrOH. Overall, this work offers a new viewpoint to develop more practical zirconium-containing coordination catalysts for the selective synthesis of valuable chemicals via CTH.

In this work, the hydrocyclization of methyl levulinate (ML) to γ-valerolactone (GVL) was performed in MeOH over an in situ prepared nanocopper catalyst without external H2 . This nanocopper catalyst served as a dual-functional catalyst for both hydrogen production by MeOH reforming and hydrogenation of ML. Nearly quantitative ML conversion with a GVL selectivity of 87.6 % was achieved at 240 °C in 1 h in MeOH under a nitrogen atmosphere. ML in the methanolysis products of cellulose also could be hydrogenated effectively to GVL over this nanocopper catalyst even in the presence of humins to give an ML conversion of 94.1 % and a GVL selectivity of 73.2 % at 240 °C in 4 h. The absorption behavior of humins on the surface of the nanocopper catalyst was observed, which resulted in a pronounced increase in the acidic sites of the nanocopper catalyst that facilitate ring-opening and the hydrocarboxylation/alkoxycarbonylation of GVL to byproducts.

In the present study, cellulolytic enzyme lignin, which was isolated from enzymatic hydrolysis residues of bamboo, could be efficiently depolymerized into oily products with a yield of over 60 wt % using a range of acidic zeolites and/or Raney Ni catalysts. The degraded products are mainly composed of phenolic monomers, which can be used as versatile chemicals or the precursor for biofuel production. The yields of monophenols were 12.9 wt % and no more than 5.0 wt % when catalyzed by Raney Ni or acidic zeolites, respectively. However, a yield of monophenols as high as 21.0–27.9% was obtained using a Raney Ni combination with acidic zeolite catalysts. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry analysis revealed that the depolymerization level of the oily fraction catalyzed by a combination of catalysts was more complete in comparison to those catalyzed by an independent catalyst. The results indicated that the catalytic activity of a fully heterogeneous catalyst combination for the depolymerization of cellulolytic enzyme lignin was proven to be superior to that of either component alone.

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An acid–base bifunctional hafnium-based coordination polymer catalyst (Hf-DTMP) showed high catalytic activity and stability for the CTH of HMF into BHMF.