Simple addition to catalyst's outer edge speeds bond breaking and electron release
Do protons speed through a catalyst, take the scenic route, or stop altogether? Using their understanding of a proton's choices, scientists at the Center for Molecular Electrocatalysis revised their nickel-based catalyst to quickly handle one of a fuel cell's tough challenges: breaking chemical bonds and freeing the stored electrons to work. The catalyst's speed comes from an additional, second proton relay, a molecular fragment, on the outer edge. With the second proton relay, the catalyst quickly transforms through three different isomers, or forms, and the proton goes on its way. Without the relay, the catalyst sticks in one form and moving the proton from the active site takes much longer. Also, the team discovered that the proton's behavior and the catalyst's response changes if water is used as a base to remove the protons, compared to a strong amine base. The catalyst's response to the different bases graces the cover...