Robust Joule-heating ceramic reactors for catalytic CO oxidation

Abstract

Joule-heating reactors have the higher energy efficiency and product selectivity compared with the reactors based on radiative heating. Current Joule-heating reactors are constructed with electrically-conductive metals or carbon materials, and therefore suffer from stability issue due to the presence of corrosive or oxidizing gases during high-temperature reactions. In this study, chemically-stable and electrically-conductive (La0.80Sr0.20)0.95FeO3 (LSF)/Gd0.1Ce0.9O2 (GDC) ceramics have been used to construct Joule-heating reactors for the first time. Taking the advantage of the resistance decrease of the ceramic reactors with temperature increase, the ceramic reactors heated under current control mode achieved the automatic adjustment of heating to stabilize reactor temperatures. In addition, the electrical resistance of LSF/GDC reactors can be tuned by the content of the high-conductive LSF in composite ceramics and ceramic density via sintering temperature, which offers flexibility to control reactor temperatures. The ceramic reactors with dendritic channels (less than 100 µm in diameter) showed the catalytic activity for CO oxidation, which was further improved by coating efficient MnO2 nanocatalyst on reactor channel wall. The Joule-heating ceramic reactors achieved complete CO oxidation at a low temperature of 165 °C. Therefore, robust ceramic reactors have successfully demonstrated effective Joule heating for CO oxidation, which are potentially applied in other high-temperature catalytic reactions.

Joule-Heated Catalytic Reactors toward Decarbonization and Process Intensification: A Review

“…Joule heating has already found extensive use in both domestic and industrial applications, and the knowledge gained from these applications can be readily applied to the field of catalytic processes. Compared to conventional metal resistors, the electrically conductive ceramics appear to be promising substitutes that offer higher stability in high temperature or corrosive conditions and in general offer higher resistivities, which allows operating the processes with reasonable currents for the same heat duty. , Moreover, advanced additive manufacturing, such as 3D printing, enables tuning the electrical resistivity of the ceramic composites in order to precisely control the temperature distribution inside the reactor, as reported by Klemm and co-workers (CHEMampere project) …”

Electrified Catalysts for Endothermic Chemical Processes: Materials Needs, Advances, and Challenges

“…42 Another advantage offered by ceramic substrates lies in the fact that their resistivity can be tuned merely by altering the composition of the ceramic substrate, as shown for example in the case of lanthanum strontium ferrites and gadoliniumdoped ceria in membrane reactor applications. 42 The electrical and catalytic properties of complex mixed metal oxides can be tuned systematically by varying their composition, presenting a significant opportunity in this regard. Silicon carbide is a specific ceramic material that is attracting increasing attention for electrification applications.…”

“…Ceramic reactors, for instance, can exhibit drastically decreasing resistivity with increasing temperature, providing an additional lever for controlling catalyst temperature, as shown by Liu et al using constant current and constant voltage modes. 42 Another advantage offered by ceramic substrates lies in the fact that their resistivity can be tuned merely by altering the composition of the ceramic substrate, as shown for example in the case of lanthanum strontium ferrites and gadoliniumdoped ceria in membrane reactor applications. 42 The electrical and catalytic properties of complex mixed metal oxides can be tuned systematically by varying their composition, presenting a significant opportunity in this regard.…”

“…Other classes of nonceramic heating elements, albeit limited in oxidative stability, can offer unique advantages in Joule heating applications. An example is “remote heating” that can be enabled through the use of carbon-based heating elements in which a majority of the current supplied can be directed toward heating a neighboring material rather than providing thermal energy exclusively to regions with nonzero current density. , Such mechanisms of heat transfer in carbonaceous materials have been ascribed to the coupling of electric currents with vibrational modes accessible in materials adjacent to the current-carrying substrate. , In situ electron thermal microscopy has been used to demonstrate, for example, that 84% of the electrical energy supplied to a single-walled carbon nanotube can be transformed directly into thermal energy in a neighboring silicon nitride layer . Although this mechanism for heat transfer has been evidenced in nonmetallic Joule-heated systems, it has not, to the best of our knowledge, been exploited in resistively heated catalytic applications.…”

Enhanced Compatibility and Activity of High-entropy Double Perovskite Cathode Material for IT-SOFC

“…LnBaCo2O5+δ (Ln=Pr, Nd, Sm, Gd, La and Y) oxides with excellent ion-electron mixed conduction, high oxygen surface exchange (K) and bulk diffusion (D) coefficient have attracted much attention, which can be used promising cathode materials for IT-SOFCs [4][5][6] . In these perovskite oxides, rare earth ions and alkaline ions took up positions at A site of the lattice [7] .…”