<p>The catalytic properties of mono- and bimetallic nanoparticles based on copper, silver, and gold in the deuterium–hydrogen exchange reaction at cryogenic temperatures were studied. Using γ-Al₂O₃, 16 samples based on Cu, Ag, and Au were synthesized as a carrier, including monometallic and bimetallic systems obtained by joint or sequential deposition. The catalytic activity was determined at 77 K and a pressure of 0.5 Torr. It was shown that monometallic Ag and Au nanoparticles exceed a sample similar to an industrial nickel-based sample in specific catalytic activity, however, silver nanoparticles are not stable. Upon going from mono- to bimetallic nanoparticles, increased stability is observed, as well as an increase in catalytic activity, which is associated with electronic and geometric effects. Temperature-programmed oxidation and reduction methods confirmed a strong interaction of the components in bimetallic systems. The results indicate the potential of using inexpensive bimetallic catalysts, for example, Cu–Ag with high activity and low cost or Ag@Au with increased thermal stability for the deuterium–hydrogen exchange reaction.</p>