The selective hydrogenation of alkynes to alkenes is an important
synthetic process in the chemical industry. It is commonly accomplished using
palladium catalysts that contain surface modifiers, such as lead and silver. Here we
report that the adsorption of nitrogen-containing bases on gold nanoparticles results
in a frustrated Lewis pair interface that activates H2 heterolytically, allowing an
unexpectedly high hydrogenation activity. The so-formed tight-ion pair can be
selectively transferred to an alkyne, leading to a cis isomer; this behavior is controlled
by electrostatic interactions. Activity correlates with H2 dissociation energy, which
depends on the basicity of the ligand and its reorganization on activation of hydrogen.
High surface occupation and strong Au atom−ligand interactions might affect the
accessibility and stability of the active site, making the activity prediction a
multiparameter function. The promotional effect found for nitrogen-containing bases
with two heteroatoms was mechanistically described as a strategy to boost gold
activity