Ni–Mg Supported Catalysts on Low-Temperature Electrocatalytic Tri-reforming of Methane with Suppressed Oxidation

Abstract

10wt%Ni−10wt%Mg−La 0.1 Zr 0.9 O 2−x (LZO) catalyst shows high reforming activity of methane while suppressing methane combustion on trireforming of methane at low temperatures of 473 K in an electric field. On the basis of results of light-on and light-off tests for methane oxidation and temperature dependencies for catalytic methane steam reforming activity with or without the electric field, we found that Mg addition to 10wt%Ni−LZO catalyst suppresses methane combustion, while the methane steam reforming proceeds well by virtue of surface protonics in the electric field. Ni 2+ on 10wt%Ni−10wt%Mg−LZO catalyst was more cationic than that on 10wt%Ni−LZO catalyst, and NiO−MgO solid solution formed on LZO support played an important role in combustion suppression.

Electrochemical Methane Conversion

“…Sekine and coworkers reported that electric field could facilitate proton hopping on the surface. [ 18 ] Using 10 wt% Ni−10wt%MgLa 0.1 Zr 0.9 O 2− x , the incorporation of Mg formed NiOMgO solid solution on MgLa 0.1 Zr 0.9 O 2− x , which suppressed the reduction of NiO at low temperatures by making it more cationic. The reforming process did not occur without the electric field.…”

Recent progress in use and observation of surface hydrogen migration over metal oxides

“…Hydrogen migration plays an important role in various catalyses such as hydrogenation-dehydrogenation of hydrocarbon, 1-5 CO 2 reduction [6][7][8][9] and NH 3 synthesis. [10][11][12][13][14][15][16][17] However, the utilisation of hydrogen migration is not limited to catalysis.…”

Key factor for the anti-Arrhenius low-temperature heterogeneous catalysis induced by H+ migration: H+ coverage over support

“…[1][2][3][4][5][6][7][8] Our group, which has specifically examined the use of an electric field for low-temperature catalysis, has facilitated various catalytic reactions such as steam reforming of hydrocarbon, dehydrogenation of methylcyclohexane (MCH), and NH 3 synthesis. [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] In an electric field, H + hopping via surface hydroxyl groups proceeds (so-called surface protonics), thereby enabling the reaction path through collision between H + over support and adsorbent over loading metals such as CH 4 , MCH, and N 2 .…”

“…Various analyses have revealed novel catalysis qualitatively in an electric field induced by H + hopping. [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] Quantitative evaluation of the H + contribution to the overall reaction rate is extremely important. The work described herein succeeded in formulizing the effect of H + amount over supports in the electric field using NH 3 synthesis and Ru/CeO 2 respectively as a model reaction and catalyst.…”

“…Similarly, we have reported C-H cleavage activation by hopping proton over a support. [9][10][11][12][13][14][15][16][17][18] Therefore, the amount of H + over the support is expected to be crucially important for novel catalysis in the electric field. We assumed, therefore, that the temperature dependence of the H + coverage over CeO 2 plays an important role in specific temperature dependence with the electric field.…”