Butane Dry Reforming Catalyzed by Cobalt Oxide Supported on Ti₂AlC MAX Phase

Abstract

MAX (M n + 1 AX n) phases are layered carbides or nitrides with a high thermal and mechanical bulk stability. Recently, it was shown that their surface structure can be modified to form a thin non-stoichiometric oxide layer, which can catalyze the oxidative dehydrogenation of butane. Here, the use of a Ti 2 AlC MAX phase as a support for cobalt oxide was explored for the dry reforming of butane with CO 2 , comparing this new catalyst to more traditional materials. The catalyst was active and selective to synthesis gas. Although the surface structure changed during the reaction, the activity remained stable. Under the same conditions, a titania-supported cobalt oxide catalyst gave low activity and stability due to the agglomeration of cobalt oxide particles. The Co 3 O 4 /Al 2 O 3 catalyst was active, but the acidic surface led to a faster deactivation. The less acidic surface of the Ti 2 AlC was better at inhibiting coke formation. Thanks to their thermal stability and acid-base properties, MAX phases are promising supports for CO 2 conversion reactions.

CO2 Hydrogenation at Atmospheric Pressure and Low Temperature Using Plasma-Enhanced Catalysis over Supported Cobalt Oxide Catalysts

“…A Thermo Scientific Surfer instrument was used to carry out N 2 adsorption–desorption analyses at 77 K. The samples were pretreated under vacuum at 200 °C for 6 h. Surface areas were determined with the Brunauer–Emmett–Teller (BET) method, and the mesoporosity was analyzed using the Barrett, Joyner, and Halenda (BJH) method. Hydrogen temperature-programmed reduction (H 2 -TPR) profiles were obtained using a TPDRO Series 1100 from Thermo Scientific, following the procedure previously reported by Ronda-Lloret et al 6 High-resolution transmission electron microscopy (HRTEM) micrographs and transmission electron microscopy coupled with energy-dispersive X-ray spectroscopy (STEM–EDS) images were obtained on a JEOL-JEM 2100F microscope running at 200 kV. X-ray photoelectron spectroscopy (XPS) analyses were performed with a SPECS PHOIBOS 100 MCD5 hemispherical electron analyzer operating in a constant pass energy.…”

Molybdenum Oxide Supported on Ti3AlC2 is an Active Reverse Water–Gas Shift Catalyst

“…Before the analysis, the samples were pretreated under a helium gas flow of 80 mL·min –1 at 350 °C for 3 h and then reduced at 500 °C for 6 h under pure hydrogen. More details on the analysis procedure can be found in Ronda-Lloret et al ( 36 )…”

“… 35 We also showed that MAX phases are promising supports for CO 2 conversion reactions. 36 The thermal stability and acid–base properties of the Ti 2 AlC MAX phase increased the stability and coking resistance of a Co 3 O 4 /Ti 2 AlC catalyst during dry reforming of butane. 36 Elsewhere, Trandafir et al recently showed the potential of Pd/Ti 3 SiC 2 as a chemoselective catalyst in the hydrogenation of functionalized nitro derivatives.…”

Enhancing catalytic epoxide ring-opening selectivity using surface-modified Ti3C2T x MXenes

“…They are prepared by delaminating MAX phases, which are atomically layered solids where M is an early transition metal, A is a group IIIA/IVA element, and X is carbon or nitrogen [1]. MXenes are denoted by M n+1 X n T x , where T stands for a terminating functional group that depends on the delamination conditions [2][3][4][5]. These materials are very versatile.…”