Nano-islands: Confining Ultrafine Metal Nanoparticles for Sintering Resistance

• • Ru/LaOx-SiO2 catalysts exhibit a 61.1 kJ mol−1 chemical potential difference between LaOx and SiO2 substrates, thermodynamically suppressing Ru NP migration and enabling stable DRM operation at >700 °C, a regime where conventional supported catalysts sinter irreversibly within hours. • • Contact angle measurements reveal 80° for Ru/SiO2 versus 40° for Ru/La2O3, quantifying the adhesion energy (Eadh) disparity that underpins the nano-island trapping mechanism; this 2-fold wettability contrast translates directly into a 61.1 kJ mol−1 barrier against particle migration. • • The pH-controlled strong electrostatic adsorption protocol achieves site-selective metal nucleation exclusively on oxide nano-islands by maintaining pH between the isoelectric points of the support and the nano-islands, enabling uniform dispersion of LaOx islands on SiO2 and preventing metal deposition on bare support regions. • • La3+ was selected for nano-island fabrication due to its lowest reduction potential among candidate cations, ensuring that LaOx remains stable under reducing DRM conditions; this selection criterion provides a generalizable design rule for constructing sintering-resistant oxide-island libraries on common substrates.