Lattice-Embedded Single-Atom Sr–O–Ni Channels Enable Photon–Phonon Coupling for Photothermal N2O Decomposition

Nitrous oxide (N2O) is a long-lived greenhouse gas whose concentrated industrial emissions are difficult to abate without substantial energy input. Thermocatalytic decomposition achieves high conversion but requires external heating to overcome the coupled barriers of N-O activation and oxygen recombination, whereas photocatalytic routes are limited by poor solar utilization and sluggish kinetics. Photothermal catalysis could integrate both advantages, but atomic-scale synchronization of these processes remains scarce. Here, we report a lattice-embedded single-atom strategy that enables such coupling through continuous dopant-oxygen-metal channels. By incorporating isolated Sr atoms into NiO lattice, atomically continuous Sr-O-Ni bridges extend electronic reconstruction into the bulk, narrow the band gap, and simultaneously promote electron transfer into N2O antibonding orbitals and rapid surface oxygen turnover. Under simulated sunlight without external heating, Sr1-NiO achieves 97.2% single-pass conversion of 10 vol % N2O in continuous flow, delivering a rate of 43.2 mmol g-1 h-1 that markedly surpasses representative thermocatalytic and photocatalytic systems under comparable conditions, together with stable operation over 200 h and robustness toward coexisting O2, NO, and H2O. Comparable performance is reproduced under outdoor sunlight. Wavelength-selective experiments, operando spectroscopy, and DFT calculations show that the Sr-O-Ni channels enable photon-driven electron excitation to facilitate N-O bond cleavage, while phonon-mediated local heating accelerates *O coupling and O2 desorption along a Langmuir-Hinshelwood pathway. This work establishes lattice-embedded single-atom channels as a general chemical motif for synchronizing charge flow and oxygen dynamics in photothermal catalysis.