An overview of recent advances in research on selective conversion of carbohydrates into products with hydrothermal chemistry is given. Conversion methods tend to use acid- or base-catalysed reactions and oxidation reactions. Conversion products that can be selectively produced include acetic acid, formic acid, lactic acid, levulinic acid, 5-hydroxymethyl-2-furaldehyde (HMF) and 2-furaldehyde (2-FA). Future conversion paths and possible new products that can be formed with hydrothermal chemistry include aldol/reverse condensation, dehydration, benzilic acid rearrangement, keto-enol tautomerization, Lobry de Bruyn–Alberda van Ekenstein transformation and oxidation reactions.

The production of formic acid or formate salts by hydrothermal oxidation of glucose, a model compound of carbohydrate biomass, was investigated in the presence and absence of alkali using a batch reactor with H₂O₂ oxidant. Results showed that glucose was converted into formate salts with an excellent yield of 75% at a mild temperature of 250 °C in the presence of alkali. The results should be helpful to facilitate studies for developing a new green process for the conversion of carbohydrate biomass into formic acid, which can be a potential intermediate for fuels, as well as other value-added products.

A solution processed MoO₃/PEDOT:PSS bilayer structure is used as the hole transporting layer to improve the efficiency and stability of planar heterojunction perovskite solar cells. Increased hole extraction efficiency and restrained erosion of ITO by PEDOT:PSS are demonstrated in the optimized device due to the incorporation of an MoO₃ layer.

Hydrothermal decomposition experiments of glycerin with an alkali showed that glycerin could be converted into lactic acid with a high yield of about 90 mol % based on glycerin used. Discussion on the pathway for the conversion of glycerin to lactic acid suggests that glycerin is first decomposed to pyruvaldehyde with elimination of hydrogen by a H− shift to the adjacent hydrogen. Pyruvaldehyde formed is then converted into lactic acid ion by the benzilic acid rearrangement.

Global shellfishery waste generation is from 6 to 8 million metric tons annually. Chitin, as a major component in crustacean shells, is the second most abundant biopolymer on Earth, having the potential to supplement the lignocellulosic biomass resource for renewable chemicals. Herein, we established direct transformation of chitin and raw shrimp shells into acetic acid (HAc) by a catalytic method using metal oxide and oxygen gas in basic water. The work showcased that chitin is a superior starting material to other major biomass resources for HAc production. A 38.1% yield of HAc was produced from chitin, which was more than a 2-fold increase compared with that from cellulose. Moreover, a 47.9% yield was directly obtained from crude shrimp shells. Another finding is that heterocyclic compound pyrrole was generated as the major nitrogen-containing (N-containing) product in the reaction system, which offers a potential chemical route for one-step pyrrole formation from a sustainable resource. The study opens new avenues to transform shellfishery waste into platform chemicals.