Carbon dioxide levels in the atmosphere keep rising, warming up our planet. And that has many researchers looking at two key catalytic reactions — photocatalysis and electrocatalysis — that can convert CO₂ into hydrocarbons. It’s an exciting idea, using either sunlight or electricity to activate a catalyst that transforms CO₂ pollution into fuels and other valuable chemicals. 

However, current techniques tend to create products with just a single carbon atom. That’s a problem, because…