A confined growth strategy to construct 3DOM SiO₂ nanoreactor in-situ embedded Co₃O₄ nanoparticles catalyst for the catalytic combustion of VOCs: Superior H₂O and SO₂ resistance

SO₂ poisoning is a common problem in the catalytic combustion of volatile organic compounds (VOCs). In this work, we took three-dimensionally ordered macroporous and mesoporous (3DOM) SiO₂ as the nanoreactor to protect active sites from SO₂ erosion in the catalytic combustion of benzene. Simultaneously, the confined growth of metal active nanoparticles in the multi-stage pore is also full of challenges. And we successfully confined Co₃O₄ nanoparticles (NPs) in macroporous and mesoporous channels. Interestingly, the precursors’ growth in the pore was controlled and nanoreactors with different pore sizes were prepared by adjusting the loading amount and preparation methods. It is discovered that the Co₃O₄ NPs confined in 3DOM SiO₂ nanoreactor showed superior sulfur and water resistance. Density functional theory (DFT) calculations verified that the Co-Si catalyst had high SO₂ adsorption energy (−0.48 eV), which illustrated that SO₂ was hard to attach to the surface of the Co-Si catalyst. The SiO₂ nanoreactor had low SO₂ adsorption energy (−5.15 eV), which indicated that SO₂ was easily absorbed on SiO₂ nanoreactor. This illustrated that the SiO₂ nanoreactor could protect effectively active sites from SO₂ erosion.