One-pot synthesis of mesoporous Cu-SiO2-Al2O3 bifunctional catalysts for hydrogen production by dimethyl ether steam reforming

Catalytic reforming of dimethyl ether in microchannels

“…CH 3 OCH 3 + (3-n) H 2 O + n/2 O 2 → (6-n) H 2 + 2 CO 2 (1) The catalytic reforming of DME at moderate temperature consists of two consecutive reactions; first, DME is hydrolyzed to methanol over an acid catalyst, and then methanol is subsequently transformed into a mixture of H 2 and CO x over a metal function with the participation of the water gas shift reaction (WGS). Acidity of the catalyst is supplied by the support, usually γ-Al 2 O 3 , ZrO 2 , WO 3 /ZrO 2 and zeolites such as ZSM-5 [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23], but also tungstosilicoheteropolyacids, Ga 2 O 3 /TiO 2 and Mo 2 C [24][25][26], whereas the metal function is usually based on Cu (normally CuZn or Cu/CeO 2 ) [27][28][29][30][31][32][33][34][35][36][37][38][39] or Pd (Pd or PdZn) [40][41][42][43], although the use of other metals such as Ni, Pt, Rh, Ru and Au [44][45][46][47][48][49][50]…”

Sputtered Cu-ZnO/γ-Al2O3 Bifunctional Catalyst with Ultra-Low Cu Content Boosting Dimethyl Ether Steam Reforming and Inhibiting Side Reactions

“…The dimethyl ether steam reforming (DME SR) reaction is as follows: DME SR: (CH 3 ) 2 O + 3H 2 O (g) → 6H 2 + 2CO 2 Generally, DME SR is accomplished by a two-step tandem reaction process, namely DME hydrolysis and subsequent methanol steam reforming (MSR): , DME hydrolysis: CH 3 OCH 3 + H 2 O → 2CH 3 OH (over the acidic sites , ) MSR: CH 3 OH + H 2 O → 3H 2 + CO 2 (over the metallic sites , ) The most commonly used solid acid catalyst is γ-Al 2 O 3. , For metallic catalysts, noble metal-based catalysts (Pt, Rh, Ru) have high MSR activity with the disadvantages of a high methanation side reaction activity and expensive cost. , Thus, Cu-based catalysts are the most frequently used catalysts in DME SR due to their high activity and CO 2 selectivity in the MSR step. − Many researchers − utilized the modified Cu/SiO 2 catalysts synthesized by an ammonia evaporation method for the MSR step. They achieved a high hydrogen yield of about 90.0%.…”

A Structured Cu-Based/γ-Al2O3/Al Multifunctional Catalyst for Steam Reforming of Dimethyl Ether: Investigation on in-Situ CO Reduction Strategy

“…Moreover, the well-developed infrastructure of LPG can readily be used for the distribution of DME due to their similar physical properties. 4,5 Generally, steam reforming of dimethyl ether (DME SR, eq 1) consists of two successive reactions: DME hydrolysis (eq 2) to methanol over a solid acid catalyst, followed by steam reforming of methanol (MSR, eq 3) to hydrogen and carbon dioxide over a metallic catalyst. Thus, a bifunctional catalyst consisting of dual sites of acid sites and MSR sites is required for DME SR process.…”

“…Hydrogen is considered to be a clean source of energy and steam reforming of dimethyl ether (DME) is regarded as a promising hydrogen production process for fuel cell applications. − Unlike many other fuels (e.g., methane, methanol, bioethanol), DME possesses high H/C ratio, high energy density, nontoxic and noncorrosive nature. Moreover, the well-developed infrastructure of LPG can readily be used for the distribution of DME due to their similar physical properties. , Generally, steam reforming of dimethyl ether (DME SR, eq ) consists of two successive reactions: DME hydrolysis (eq ) to methanol over a solid acid catalyst, followed by steam reforming of methanol (MSR, eq ) to hydrogen and carbon dioxide over a metallic catalyst. Thus, a bifunctional catalyst consisting of dual sites of acid sites and MSR sites is required for DME SR process. …”

“…In addition, many studies , have discussed the steam reforming process with a conventional packed bed reformer, which suffers from several drawbacks, such as poor heat transfer, high pressure drop, diffusion limitation, a large volume, long start-up time, and etc . Recently, increasing public interest in energy-related issues requires further efficiency in energy utilization.…”