Combinatorial discovery of new autoreduction catalysts for the CO 2 reforming of methane

Abstract

High-throughput synthesis and screening techniques were used in the search for and optimization of new autoreduction catalysts for the CO 2 reforming of methane. Diverse libraries had been synthesized via three different modified sol–gel methods using a synthesis robot and library design software. The catalyst libraries were screened for catalytic activity and stability in a simple high-throughput reactor system at 600 °C connected to a micro-gas chromatograph for product analysis. During generations 1 and 2, more than 5000 highly diverse mixed oxides were tested for potential catalytic activity. Ni 10Ce 90O x demonstrated effective activity and stability among nonprecious metal catalysts without a prereduction step. In a conventional study, two advantages (i.e., rapid startup operation and high coking resistance) of Ni 10Ce 90O x were noted relative to the well-known Ni/Al 2O 3, but deactivation was recognized. To reduce deactivation of Ni 10Ce 90O x , catalyst libraries with additional dopants were prepared and examined during generations 3 and 4. Among these, (Al 5, Al 15, Zr 15)Ni 10Ce 90− y O x , in which metal nitrate was used as a dopant precursor, and (Al 15, Zr 5, Zr 15)Ni 10Ce 90− y O x , in which metal alkoxide was used, exhibited comparable activity and strongly reduced deactivation compared with Ni 10Ce 90O x . Good performance of the best new catalysts, particularly Al 15Ni 10Ce 75O x , in which aluminium alkoxide was used as a dopant precursor, and Zr 15Ni 10Ce 75O x , in which zirconium dinitrate oxide was used, was found in high-throughput studies and confirmed in conventional experiments.