Recently, carbon dioxide capture and conversion, along with hydrogen from renewable resources, provide an alternative approach to synthesis of useful fuels and chemicals. People are increasingly interested in developing innovative carbon dioxide hydrogenation catalysts, and the pace of progress in this area is accelerating. Accordingly, this perspective presents current state of the art and outlook in synthesis of light olefins, dimethyl ether, liquid fuels, and alcohols through two leading hydrogenation mechanisms: methanol reaction and Fischer-Tropsch based carbon dioxide hydrogenation. The future research directions for developing new heterogeneous catalysts with transformational technologies, including 3D printing and artificial intelligence, are provided.

Rare earth elements (REEs) are in high demand as critical materials in modern green and other advanced technologies. This review focuses on the recovery of REEs from waste with ionic liquids (ILs) as green dilutants and extractants to tackle the REE supply challenge. Extraction mechanisms in different extraction systems, including pure ILs, non-functional ILs with extractants, and functional ILs, are discussed in depth. The IL-based extraction process is different from the traditional molecular solvent-based extraction process. In addition, stripping is crucial to recovering ILs, and supercritical CO₂ (Sc-CO₂) is introduced to recover REE complexes from the IL phase. Also, Sc-CO₂ can accelerate the whole extraction process by enhancing mass transfer. The challenge is to understand the extraction mechanism of the IL/Sc-CO₂ system to advance the green recovery of REEs from waste.

The quickly increasing demand for sustainable energy and materials requires researchers to develop highly efficient and stable catalytic materials for the hydrogenation of carbon–oxygen bonds into chemicals and fuels. Cu-based catalysts have been attracting tremendous attention in gas-phase catalytic reactions, such as the water-gas shift, CO oxidation and NO_x reduction reactions. In particular, the C–O bond hydrogenation reaction is an economical and environmentally friendly way to produce alcohols. However, the instability of Cu-based catalysts has become a great challenge for industrial application. The majority of publications discuss the instability of Cu-based catalysts for reactions involving the hydrogenation of dimethyl oxalate, methyl acetate, furfural, or CO₂ to alcohols. This review briefly summarizes the roots of Cu-based catalyst deactivation and introduces five strategies for improving their stability, as well as the evolution of copper species during preparation and reaction and a novel Cu-based catalyst technology.