Identifying Different Types of Catalysts for CO₂ Reduction by Ethane through Dry Reforming and Oxidative Dehydrogenation

Abstract

The recent shale gas boom combined with the requirement to reduce atmospheric CO2 have created an opportunity for using both raw materials (shale gas and CO2 ) in a single process. Shale gas is primarily made up of methane, but ethane comprises about 10 % and reserves are underutilized. Two routes have been investigated by combining ethane decomposition with CO2 reduction to produce products of higher value. The first reaction is ethane dry reforming which produces synthesis gas (CO+H2 ). The second route is oxidative dehydrogenation which produces ethylene using CO2 as a soft oxidant. The results of this study indicate that the Pt/CeO2 catalyst shows promise for the production of synthesis gas, while Mo2 C-based materials preserve the CC bond of ethane to produce ethylene. These findings are supported by density functional theory (DFT) calculations and X-ray absorption near-edge spectroscopy (XANES) characterization of the catalysts under in situ reaction conditions.

The effects of bimetallic interactions for CO2‐assisted oxidative dehydrogenation and dry reforming of propane

“…However, if Fe were to be the metal replacing Pt 1 then the wt% would be 0.48% and the nomenclature would be Fe 1 . For this investigation metal loadings, calcination, and drying treatment conditions were consistent with previous studies …”

Activation Pathway of C‐H and C–C Bonds of Ethane by Pd Atom with CO2 as a Soft Oxidant

“…First, the H atom of CH 3 CH 3 near the catalyst Pd is activated, the C−H bond is elongated, the first C−H bond is broken to form CH 3 CH 2 ‐Pd−H, and then the C−C bond is broken to form CH 3 ‐Pd‐CH 3 . Part of CH 3 ‐Pd‐CH 3 will further react to form Pd‐CH 2 +CH 4 , which is similar to results of the reference, and researchers detected a small amount of CH 4 in the initial stage of reaction that favors reforming. The two C−H bonds close to catalyst in the methane are elongated to 1.103 Å, indicating that the bond has been activated, therefore, a small amount of CH 4 that generated in the initial stage is easily reacted.…”

“…The content of ethane in natural gas, coalbed methane and shale gas cannot be ignored, it is the second only to methane in natural gas . Compared with methane reforming, the temperature required for ethane reforming is lower, which is beneficial to dry reforming (CO 2 ) to syngas and methane separation . There are different paths for the reaction of ethane and CO 2 , one reaction channel is oxidative dehydrogenation to form an important industrial raw material ethylene by activating C−H bonds: C 2 H 6 +CO 2 →C 2 H 4 +CO+H 2 O.…”

“…Naoki et al studied the oxidative dehydrogenation of ethane over Cr/ZSM‐5 catalyst with CO 2 as oxidant. Porosoff et al compared the different catalysts, indicating that Pt/CeO 2 tend to reforming reaction, while Mo 2 C‐based materials are easier to form ethylene. However, there is still relatively lacking to study the two reaction pathways of ethane and CO 2 on the same catalyst simultaneously.…”

Active sites for tandem reactions of CO 2 reduction and ethane dehydrogenation

“…S hale gas has the potential to revolutionize the energy and chemical industry as its verified reserves have continually increased recently. Ethylene, one of the most important intermediates for chemical industry, can be produced from the underutilized ethane (∼10% depending on the particular source) in shale gas (1,2). The traditional routes for ethylene production from thermal steam cracking (3,4) and direct dehydrogenation (5) of ethane are energy-intensive and inevitably accompanied with serious coking problems (1,6).…”