Optimizing Interfacial Sites of Ni/ZrO 2 via Morphology‐Induced Crystal Phase Modulation to Enhance Photothermal CO 2 Conversion

ABSTRACT Photothermal CO 2 conversion into value‐added syngas via dry reforming is pivotal for greenhouse gas utilization, yet its efficiency is constrained by catalyst deactivation. Here, we demonstrate that morphology‐induced crystal phase modulation of ZrO 2 supports enables effective optimization of interfacial sites in Ni/ZrO 2 catalysts. By engineering cubic (Ni/ZrO 2 ‐C) and stellated (Ni/ZrO 2 ‐S) architectures, a metastable mixed‐phase structure (54.8% monoclinic/37.3% tetragonal) is stabilized to achieve precise phase regulation. Systematic characterization reveals that this phase transformation strengthens metal–support interactions, improves Ni dispersion, and generates abundant oxygen vacancies. As a result, Ni/ZrO 2 ‐C achieves 95% ethanol conversion with lower by‐product formation and exhibits exceptional stability, with a 50% lower deactivation rate (0.13% h −1 ) than Ni/ZrO 2 ‐S (0.26% h −1 ). The enhanced performance is attributed to improved surface basicity and more efficient coke gasification facilitated by interfacial oxygen vacancies. ​Theoretical calculations further confirm kinetically favorable pathways with reduced activation barriers, particularly for carbon oxidation, accounting for the observed 3.2‐fold higher activity of Ni/ZrO 2 ‐C. This work establishes morphology‐directed crystal phase engineering as a general strategy for designing efficient photothermal catalysts.