Alumina nanoparticle-induced decarbonation at subduction-zone conditions

Jun Hu; Jin Liu; Yifeng Zhu; Penghui Sun; Ao Deng; Chaojia Lv; Liangxu Xu; Fengxia Sun; Lei Li; Yongjun Tian

doi:10.1038/s42004-026-02005-7

Alumina nanoparticle-induced decarbonation at subduction-zone conditions

Commun Chem. 2026 Apr 11. doi: 10.1038/s42004-026-02005-7. Online ahead of print.

Authors

Jun Hu¹, Jin Liu², Yifeng Zhu³, Penghui Sun¹, Ao Deng¹, Chaojia Lv¹, Liangxu Xu^{4

5}, Fengxia Sun⁶, Lei Li³, Yongjun Tian¹

Affiliations

¹ Center for High Pressure Science, State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao, China.
² Center for High Pressure Science, State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao, China. jinliu@ysu.edu.cn.
³ School of Earth Sciences, East China University of Technology, Nanchang, China.
⁴ School of Earth and Space Sciences, Peking University, Beijing, China.
⁵ Center for High Pressure Science and Technology Advanced Research, Beijing, China.
⁶ Institute of Earthquake Forecasting, The China Earthquake Administration, Beijing, China.

PMID: 41965472
DOI: 10.1038/s42004-026-02005-7

Abstract

The evolution of calcium carbonate in subduction zones exerts profound effects on Earth's long-term climate dynamics and planetary habitability. Here, we report the first experimental study to elucidate the influence of aluminum oxide particle size on carbonate stability under high pressure-temperature (P-T) conditions using a piston-cylinder press. CaCO₃ remains thermodynamically stable across the investigated P-T conditions when coexisting with micron-sized Al₂O₃ and Al(OH)₃. In contrast, Al₂O₃ nanoparticles destabilize calcium carbonate at 0.5-2.8 GPa and 350-1050 °C, forming CaAl₄O₇, CO₂, and trace graphite. Our results reveal that the grain size effect of Al₂O₃ strongly regulates calcium carbonate stability in subduction-zone environments, driven by ultrahigh specific surface areas and elevated defect densities inherent to nanoparticles. This work fundamentally revises the current understanding of the spatiotemporal distribution of decarbonation in this region, yielding a pattern of shallower, more heterogeneous carbon release.