Driven to reduce atmospheric levels of greenhouse gases, researchers worldwide are developing methods for sequestering CO2, including injecting the gas underground and converting it to valuable liquid fuels and chemicals. But subterranean storage is expensive, and converted carbon could end up back in the atmosphere if it’s turned into volatile liquids or fuels that will release CO2 anew when burned. So Dorna Esrafilzadeh and Torben Daeneke of the University of New South Wales and coworkers developed a low-cost electrocatalytic method for converting CO2 to solid carbon, a nonvolatile material that can be used to make electrodes for energy storage or be safely buried (Nat. Commun. 2019, DOI: 10.1038/s41467-019-08824-8). To perform the reaction, the team fashioned an electrochemical cell featuring an unusual electrode. Its tip is made of a liquid-metal Ga-In-Sn alloy dosed with elemental cerium nanoparticles that make it catalytically active. Unlike a solid Ga-Ce catalyst, which quickly deactivates as a carbon layer fouls its surface, the team’s liquid catalyst resists fouling and remains stable. Using the test cell at room temperature and low voltage, the team converted CO2 to porous, graphite-like solids and showed that the materials work well as electrodes for high-efficiency capacitors.