Abstract
Many Cu alloys have been studied for electrocatalytic activity of 
reduction in 
aqueous solution. Anomalously low overpotentials with highly selective Cu alloy catalysts have been seen for the reduction of 
to
, 
, or 
. Cu‐Ni alloys produce 
and 
selectively at reversible potentials and Cu‐Sn and Cu‐Pb produce 
and 
with an enhanced reaction rate at the reversible potentials of formation. Other alloy catalysts such as Cu‐Zn, Cu‐Cd, or Cu‐Ag also exhibit behaviors distinct from those of the elemental metals. The results reported here indicate further possibilities for the development of powerful new electrocatalysts for the reduction of 
.