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 Mo2C‐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.

Simultaneously upgrading CO2 and light alkanes into value‐added products

“…The CO 2 ‐assisted DR and ODH of ethane have been extensively studied over a wide range of catalysts, including monometallic, bimetallic, and metal carbide catalysts 16‐19,30‐33 . The effect of oxide support has also been investigated over reducible and irreducible oxides for both DR 34 and ODH 35 .…”

“…In this Perspective, we discuss recent advances of CO 2 ‐assited dehydrogenation, aromatization, and hydroformylation reactions. Depending on the selective bond cleavage of light alkanes, the gaseous products can be syngas (CO and H 2 ) and olefins from the CO 2 ‐assisted dry reforming (DR, both CC and CH bond scission) and oxidative dehydrogenation (ODH, CH bond scission only) pathways, respectively 16‐19 . Moreover, the gaseous product stream (CO, H 2 , and olefins) can be further upgraded into value‐added liquid products, such as aromatics (e.g., benzene, toluene, and xylenes [BTX]) via a tandem aromatization process 20 or oxygenates via a downstream hydroformylation process using tandem reactors 21 .…”

Oxidative Dehydrogenation of Ethane with CO2 as a Soft Oxidant over a PtCe Bimetallic Catalyst

“…7,8 In particular, oxidative ethane dehydrogenation (OED) with CO 2 can increase the equilibrium ethane conversion by H 2 removal via the reverse water gas shift reaction (rWGS). 9 Another benefit of CO 2 is the removal of coke formed on the catalyst via the reverse Boudouard reaction (CO 2 + C s ⃗ 2CO), which can also enhance the catalyst stability. 10,11 However, CO 2 addition typically reduces ethylene selectivity because ).…”

“…Recently, CO 2 utilization has attracted considerable attention as an attempt to mitigate global warming. An example is the use of CO 2 as a soft oxidant to enhance the efficiency of the target product synthesis. , In particular, oxidative ethane dehydrogenation (OED) with CO 2 can increase the equilibrium ethane conversion by H 2 removal via the reverse water gas shift reaction ( r WGS) . Another benefit of CO 2 is the removal of coke formed on the catalyst via the reverse Boudouard reaction (CO 2 + C s ⃗ 2CO), which can also enhance the catalyst stability. , However, CO 2 addition typically reduces ethylene selectivity because CO 2 may react with ethane via two distinct pathways: (1) oxidative dehydrogenation (C 2 H 6 + CO 2 ⃗ C 2 H 4 + CO + H 2 O) and (2) dry reforming (C 2 H 6 + 2CO 2 ⃗ 4CO + 3H 2 ). − The former reaction proceeds via the scission of the C–H bond to yield ethylene, while syngas ( i.e.…”