The influence of metals and acidic oxide species on the steam reforming of dimethyl ether (DME)

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]…”

“…The interaction of Cu with the support and the distribution of copper species (Cu metal vs. Cu + ) play a determinant role for DME reforming [30,66]. Since Cu nanoparticles tend to sinter under DME reforming conditions Zn is usually added to ensure a robust catalyst [16,30,[35][36][37]46,[66][67][68]. Also, the addition of alkaline elements and alkaline earth metal oxides in the catalyst formulation has been described to have a positive effect, either by modifying the acidity of the support and thus suppressing the formation of undesired hydrocarbons, or by changing the reducibility of the metal function of the catalyst [18,37,53].…”

Highly efficient Zr-substituted catalysts CuZnAl1−Zr O used for hydrogen production via dimethyl ether steam reforming

“…8 in CuZnAl 0.8 Zr 0.2 O due to that the Tammann temperature of Cu (174.6 C) is much lower than that of Cu 2 O (869.3 C) [31]. According to literature [33], Cu þ and Cu 0 are assumed to work as active sites for steam reforming of MeOH, however, different intermediates are often formed on different active sites, resulting in various products [34,35]: Cu þ is favorable to the formation of HCOOÀ and COOÀ intermediates, while Cu 0 can facilitate the formation of CH 3 O species derived from CH 3 OH. The intermediates HCOOÀ and COOÀ can directly decompose to produce CO 2 , leading to high CO 2 selectivity.…”

Incorporating differential evolution (DE) optimization strategy to boost hydrogen and DME production rate through a membrane assisted single-step DME heat exchanger reactor

“…Undoubtedly, the direct method has higher economic feasibility in comparison with the conventional illustration (indirect method) since the production costs of the single-step process are 20% lower compared with the two-step one. Indeed, the initial investment will be smaller (Fukunaga et al, 2008;Tan et al, 2005).…”