Syngas, an extremely important chemical feedstock composed of carbon monoxide and hydrogen, can be generated through methane (CH₄) dry reforming with CO₂. However, traditional thermocatalytic processes require high temperatures and suffer from coke-induced instability. Here, we report a plasmonic photocatalyst consisting of a Cu nanoparticle ‘antenna’ with single-Ru atomic ‘reactor’ sites on the nanoparticle surface, ideal for low-temperature, light-driven methane dry reforming. This catalyst provides high light energy efficiency when illuminated at room temperature. In contrast to thermocatalysis, long-term stability (50 h) and high selectivity (>99%) were achieved in photocatalysis. We propose that light-excited hot carriers, together with single-atom active sites, cause the observed performance. Quantum mechanical modelling suggests that single-atom doping of Ru on the Cu(111) surface, coupled with excited-state activation, results in a substantial reduction in the barrier for CH₄ activation. This photocatalyst design could be relevant for future energy-efficient industrial processes.

合成气是一种极其重要的化学原料，由一氧化碳和氢气组成，可以通过甲烷 (CH ₄ ) 与 CO _{2的干重整制得}. 然而，传统的热催化过程需要高温并且存在焦炭引起的不稳定性。在这里，我们报告了一种等离子体光催化剂，该催化剂由一个铜纳米粒子“天线”组成，纳米粒子表面具有单钌原子“反应器”位点，非常适合低温、光驱动的甲烷干重整。这种催化剂在室温下光照时提供高光能效率。与热催化相比，在光催化中实现了长期稳定性（50 小时）和高选择性（>99%）。我们建议光激发的热载流子与单原子活性位点一起导致观察到的性能。量子力学模型表明，Ru 在 Cu(111) 表面上的单原子掺杂，加上激发态激活，导致 CH 的势垒显着降低₄激活。这种光催化剂设计可能与未来的节能工业过程相关。