Continuous CO<sub>2</sub> Capture and Selective Hydrogenation to CO over Na-Promoted Pt Nanoparticles on Al<sub>2</sub>O<sub>3</sub>
Lingcong Li, Shinta Miyazaki, Shunsaku Yasumura, Kah Wei Ting, Takashi Toyao, Zen Maeno, Ken‐ichi Shimizu
Abstract
The capture of CO2 and its reduction with H2 to form C1 compounds (i.e., CO2 capture and reduction; CCR), such as CO and CH4, using dual-functional materials (DFMs) has recently attracted attention as a promising process for CO2 emission reduction and utilization. Although CO is more useful than CH4 from a chemical synthesis perspective, the development of an effective DFM system to generate CO has been explored much less than that for CH4 generation. This study successfully developed Na-promoted Pt nanoparticles (NPs) supported on Al2O3 (Pt–Na/Al2O3) as an effective DFM for selective CO production by capturing diluted CO2 from a mixture with O2 and successive reduction by H2. The developed Pt–Na/Al2O3 was applicable for continuous CCR operation using two reactors in parallel and switching feed gases. The CO2 capture ability and productivity of CO were maintained for at least 100 h. We also elucidated the effect of basic promoters through microscopic and spectroscopic characterizations. The Na-modified Pt nanoparticles (NPs) were formed on Al2O3, where Na species play two important roles in efficient CO2 capture and selective CO formation: (i) capturing CO2 from a mixture with O2 and (ii) inhibiting the adsorption of generated CO on Pt NPs.