Mass production of Au–Cu-based catalysts with tailored selectivity is a complex and challenging task. We report a semi-affinity strategy to realize the synthesis of Au–Cu Janus nanocrystals with continuously tuned interfaces (from dimer, Janus, acorn-like Janus, to core-shell) based on Au nanosphere seeds. We highlight the role of interfacial strain due to a large lattice mismatch in growth control. The systematic electrochemical evaluation shows that the interfacial Cu oxide state, ∗CO coverage, and intermediate adsorption configuration can be well tuned by tailoring the Janus nanostructure. Optimized Au–Cu Janus catalyst reaches an efficiency of up to 80.0% for C₂₊ product with a partial current density of 466.1 mA cm⁻². The reaction products can be selectively switched from methanol (dimer) to ethanol (Janus) and further to ethylene (acorn-like Janus) by increasing the interface area of the Au–Cu heterostructures. The catalytic mechanisms are unraveled by operando surface-enhanced Raman spectroscopy (SERS) analysis and density functional theory calculations.

大规模生产具有定制选择性的金铜基催化剂是一项复杂且具有挑战性的任务。我们报告了一种半亲和策略，以基于金纳米球种子实现具有连续调节界面（从二聚体、Janus、橡子状Janus到核壳）的Au-Cu Janus纳米晶体的合成。我们强调了由于大的晶格失配而导致的界面应变在生长控制中的作用。系统的电化学评估表明，界面 Cu 氧化物状态、*CO 覆盖率和中间吸附构型可以通过定制 Janus 纳米结构来很好地调节。优化的Au-Cu Janus催化剂对于C ₂₊产物的效率高达80.0% ，部分电流密度为466.1 mA cm ^-2。通过增加 Au-Cu 异质结构的界面面积，反应产物可以选择性地从甲醇（二聚体）转换为乙醇（Janus），并进一步转换为乙烯（橡子状 Janus）。通过操作表面增强拉曼光谱（SERS）分析和密度泛函理论计算揭示了催化机制。