A quasi chemical vapor deposition method for the manufacture of well-defined covalent triazine framework (CTF) coatings on cordierite monoliths is reported. The resulting supported porous organic polymer is an excellent support for the immobilization of two different homogeneous catalysts: (1) an IrCp*-based catalyst for the hydrogen production from formic acid and (2) a Pt-based catalyst for the direct activation of methane via Periana chemistry. The immobilized catalysts display a much higher activity in comparison with the unsupported CTF operated in slurry because of improved mass transport. Our results demonstrate that CTF-based catalysts can be further optimized by engineering at different length scales.
Industrial-scale reforming of methane is typically carried out with an excess of oxidant to suppress coking of the catalyst. On the other hand, many academic studies on dry reforming employ a CO 2 /CH 4 ratio of unity to quickly observe coking which can be reduced by adding a catalyst promoter. In this work, Ni/Al 2 O 3 catalysts were tested for dry reforming of methane (CO 2 /CH 4 = 1) with additional regeneration steps to test the resistance against an oxidation treatment. Thereby, we wanted to evaluate catalyst stability for industrial relevance. The effects of three promoters, Cr, Mn and Fe, that differ in their degree of CO 2 interaction, are compared. A higher iron loading on Ni/Al 2 O 3 leads to higher stability in dry reforming with lower coke formation. However, the higher the concentration of a promoter with high CO 2 affinity, the quicker the catalyst is oxidized during regeneration with CO 2 . Subsequent reduction of a catalyst oxidized with CO 2 leads to considerable sintering in all cases. This sintering induces formation of more coke during dry reforming. On such sintered samples only highly effective promoters in large concentrations still have a noticeable effect compared to unpromoted Ni/Al 2 O 3 .
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.