Almost every loaf of bread on the planet owes something to ammonia. It is the starting point for nitrogen fertiliser, and a growing number of energy planners also see it as a practical way to store and ship hydrogen. The catch is that making it is one of heavy industry's dirtiest jobs. Now a team at the Institute of Science Tokyo says it has built a catalyst that makes ammonia under noticeably milder conditions, without any precious metals, and does it faster than the benchmark catalysts it was...