We review the indirect and direct routes for CO₂ hydrogenation to hydrocarbons and recent developments in catalyst design, performance and mechanism.

Using hydrocarbons as reagents: Adding small alkyl groups to complex molecules usually relies on alkyl halide reagents. Laudadio et al. now report a convenient method to add ethane and propane directly across conjugated olefins with no prefunctionalization or byproducts (see the Perspective by Oksdath-Mansilla). The C–H bond scission in this hydroalkylation is accomplished by a decatungstate photocatalyst that also acts as a hydrogen atom transfer agent to complete the process. The reaction, optimized under flow conditions, works with methane as well, albeit with lower efficiency. Science , this issue p. 92 ; see also p. 34

A novel hexagonal In ₂ O ₃ with high proportion of exposed {104} facets shows superior performance for CO ₂ hydrogenation to CH ₃ OH.