Electrochemical promotion of Pt nanoparticles dispersed on a diamond-like carbon matrix: A novel electrocatalytic system for H2 production

Electrochemical activation of an oblique angle deposited Cu catalyst film for H2 production

“…Fig. Similar to other EPOC studies based on K +conductor materials, [12][13][14]18,22,46,47 the application of a positive potential (V WR = +1 V) at the beginning of the experiment led to the removal of the potassium promoter from the catalyst/working electrode that could have thermally migrated from the solid electrolyte. This voltammogram was found to be very reproducible from the second cycle.…”

“…13,14 In the present study, the Cu-catalyzed H 2 production was enhanced up to three times at 320°C, the H 2 selectivity being increased from 27.4% (unpromoted conditions, V WR = +1 V) up to 39.1% (optimum electropromoted conditions, V WR = 0 V). This feature of the EPOC phenomenon has been previously shown in other studies on POM over alkali-promoted noble metal catalysts.…”

“…Nevertheless, the rate-limiting step in this kind of process is usually considered the methoxy decomposition (eqn (4) and (9)). This is a common effect observed both in EPOC 13,14,18,22,46,47 and in conventional alkali chemical promotion studies. 53,54 It can also be observed in Fig.…”

“…1 Hence, while the conventional catalytic promotion is carried out by adding a specific amount of a promoter during the preparation step of the catalyst, in the case of the electrochemical promotion, the electrically induced back-spillover of the promoter species enables the in situ control and enhancement of the catalytic performance of the catalyst film during the reaction step. [4][5][6][7][8] Several EPOC studies have also dealt with the improvement of catalytic materials and the development of electrodes consisting of catalysts highly dispersed on gold, 9 mixed ionic electronic conductors, 10 carbonous materials [11][12][13] and yttria-stabilized zirconia (YSZ), [14][15][16][17] or catalysts based on non-noble (lower cost) metals such as Ni, 11,[18][19][20][21] Fe 4,22,23 and Cu. 3 Nowadays, some of the main challenges of EPOC for further technological progress are the design of scaled-up reactors and material cost minimization.…”

“…Different techniques have been used in EPOC studies for the preparation of the active catalyst film such as deposition and calcination of an organometallic paste, 4,17,20,22 impregnation of a metal precursor solution, 9,10,18 spray deposition in a carbon matrix 12 and other less conventional techniques which enable a better control of the microstructure of the film, including Physical Vapour Deposition (PVD) methods such as sputtering, [5][6][7]14,24,25 Cathodic Arc Deposition (CAD) 13 and Pulsed Laser Deposition (PLD). Different techniques have been used in EPOC studies for the preparation of the active catalyst film such as deposition and calcination of an organometallic paste, 4,17,20,22 impregnation of a metal precursor solution, 9,10,18 spray deposition in a carbon matrix 12 and other less conventional techniques which enable a better control of the microstructure of the film, including Physical Vapour Deposition (PVD) methods such as sputtering, [5][6][7]14,24,25 Cathodic Arc Deposition (CAD) 13 and Pulsed Laser Deposition (PLD).…”