Bimetallic catalysts supported on novel spherical MgAl2O4-coated supports for dehydrogenation processes

Stability studies of PtSn structured catalysts supported on thin layers of MAl2O4 (M: Mg, or Zn) for paraffins dehydrogenation reactions

“…The main reduction peak can be attributed to the co‐reduction of Pt and Sn with strong interaction, probably forming PtSn alloys. [ 47 ] The reduction zone at the highest temperature was attributed to Sn oxides strongly anchored to the support. The TPR profiles of both bimetallic catalysts after cycles are similar (see Figure 8A,B).…”

“…SEM microphotographs of cut of spheres coated (A) with MgAl 2 O 4 by the boehmite‐nitrate method with purification (BNP) method, (B) with MgAl 2 O 4 by the citrate‐nitrate (CN) method, (C) with ZnAl 2 O 4 by the BNP method, and (D) with ZnAl 2 O 4 by the CN method. Reprinted from de Miguel et al [ 47,48 ] with permission from Elsevier…”

“…This way, five reaction-regeneration cycles were carried out. Each reaction-regeneration cycle consisted of the following steps: [47,48] with permission from Elsevier The mass of the catalyst was 0.5 g. The reaction products (methane, ethane, ethylene, propane, propylene, 1-butene, cis-and trans-2-butene, and butadiene) were analyzed in a gas chromatograph provided with an FID detector.…”

“…In Figure7A, it can be seen that the fresh Pt/Sp-Mg-CN catalyst displays three reduction peaks, the main one located at 254 C, a very small reduction zone between 70-130 C, and a wide and small zone at high temperatures between 370-500 C. The peak at the lowest temperature can be attributed to Pt oxides. The main peak is attributed to Pt oxychlorides (PtOxCly), since chloroplatinic acid was used as the precursor, and the zone of reduction at higher temperature can also be attributed to Pt oxychlorides with more interaction with the support [47,59,60]. The Pt/Sp-Mg-CN catalyst after cycles shows two important reduction peaks, one located at 120 C and another at 420 C. The first peak is attributed to the reduction of Pt oxides, and the second one to Pt species of difficult reducibility in strong interaction with the support.…”

Hydrogenation of CO to olefins over a supported iron catalyst on MgAl2O4 spinel: effects of the spinel synthesis method

“…Because of its favorable properties, such as excellent mechanical strength with low expansion at high temperature, satisfactory thermal and chemical stability, and high resistance to chemical attack, MgAl 2 O 4 has been used as a carrier for the catalytic process at high temperature such as in steam reforming, methanation, dehydrogenation and cracking processes. [25][26][27][28][29] Abbas and Chen 30 studied the hierarchical porous spinel MFe 2 O 4 (M ¼ Fe, Zn, Ni and Co) synthesized by hydrothermal reaction. In the FT area, it has been reported that alkaline promoters such as K 2 O, MnO and MgO could improve the olen selectivity.…”