Binding of carboxylates to gold nanoparticles: A theoretical study of the adsorption of formate on Au20

► Very few anionic carboxylates bind to Au20 either in gas phase or solution. ► In gas phase, electron density builds up on uncomplexed apex atoms. ► Solvation decreases charge build-up and enables binding of more carboxylates. ► Even in solution, only four carboxylates bind to Au20.