Fabrication of nanocatalysts with unique architectures provides great opportunities for modulation of catalyst surface states and therefore their catalytic performances including the activity and product selectivity. In this regard, the rational design for the nanoarchitectures upon facile strategies becomes an emerging research direction lately. In this talk, a series of stories about Pd- and Cu-based bimetallic nanocatalysts made by nanoarchitectonic engineering for small molecule conversions such as O₂, CO₂, and N₂ reduction reactions will be introduced.