Palladium Nanocatalyst Electrodeposited from

MIGUEL VAGO; MARIO TAGLIAZUCCHI; FEDERICO WILLIAMS; ERNESTO JULIO CALVO

Sevilla, España

Congreso; 59th Annual Meeting of the International Society of Electrochemistry; 2008

International Society of Electrochemistry

We report a new method to form Pd nanoparticles by electrochemical reduction of PdCl4 2- on carbon electrodes (glassy carbon and carbon felts supports). We employ a self-assembled polyelectrolyte multilayer (PEM) nanoreactor1 comprised of poly(allylamine) and poly(acrylic) acid, with further uptake of palladium ions from aqueous solution and electrochemical reduction under potentiostatic control. The as-prepared electrodes have been characterized by XPS, SEM and cyclic voltammetry and the palladium content was determined by ICP elemental analysis. Furthermore, the nanoelectrocatalyst has been assessed by studying the electrochemical hydrogenation of acetophenone2 as a model compound. Both, SEM images (see figure) and XPS show that the electrochemically generated Pd nanoparticles are preferentially located at the electrode/film interface, in contrast with the homogeneous distribution observed when a chemical reduction route is used1. Cyclic voltammetry shows the typical response of a polycrystalline Pd electrode3. The anodic hydrogen peak is completely suppressed in the presence of acetophenone which confirms the electrocatalytic activity. These properties were tested in batch process and followed by HPLC. Complete reduction of acetophenone to ethyl benzene with a current efficiency of 84% has been observed. In addition, the electrocatalytic performance was compared with that of an electrode bearing Pd microcrystals prepared by direct electroreduction of Pd(II) salts2,3 on the carbon surface resulting in a reduction rate per mole of Pd ten-fold faster than for the microcrystalline Pd electrode prepared by the standard method (1) Joly, S.; Kane, R.; Radzilowski, L.; Wang, T.; Wu, A.; Cohen, R. E.; Thomas, E. L.; Rubner, M. F. Langmuir 2000, 16, 1354. (2) Polcaro, A.; Palmas, S.; Dernini, S. Ind. Eng. Chem. Res. 1993, 32, 1315. (3) Pattabiraman, R., Applied Catalysis A. 1997, 153, 9.4 2- on carbon electrodes (glassy carbon and carbon felts supports). We employ a self-assembled polyelectrolyte multilayer (PEM) nanoreactor1 comprised of poly(allylamine) and poly(acrylic) acid, with further uptake of palladium ions from aqueous solution and electrochemical reduction under potentiostatic control. The as-prepared electrodes have been characterized by XPS, SEM and cyclic voltammetry and the palladium content was determined by ICP elemental analysis. Furthermore, the nanoelectrocatalyst has been assessed by studying the electrochemical hydrogenation of acetophenone2 as a model compound. Both, SEM images (see figure) and XPS show that the electrochemically generated Pd nanoparticles are preferentially located at the electrode/film interface, in contrast with the homogeneous distribution observed when a chemical reduction route is used1. Cyclic voltammetry shows the typical response of a polycrystalline Pd electrode3. The anodic hydrogen peak is completely suppressed in the presence of acetophenone which confirms the electrocatalytic activity. These properties were tested in batch process and followed by HPLC. Complete reduction of acetophenone to ethyl benzene with a current efficiency of 84% has been observed. In addition, the electrocatalytic performance was compared with that of an electrode bearing Pd microcrystals prepared by direct electroreduction of Pd(II) salts2,3 on the carbon surface resulting in a reduction rate per mole of Pd ten-fold faster than for the microcrystalline Pd electrode prepared by the standard method (1) Joly, S.; Kane, R.; Radzilowski, L.; Wang, T.; Wu, A.; Cohen, R. E.; Thomas, E. L.; Rubner, M. F. Langmuir 2000, 16, 1354. (2) Polcaro, A.; Palmas, S.; Dernini, S. Ind. Eng. Chem. Res. 1993, 32, 1315. (3) Pattabiraman, R., Applied Catalysis A. 1997, 153, 9.on carbon electrodes (glassy carbon and carbon felts supports). We employ a self-assembled polyelectrolyte multilayer (PEM) nanoreactor1 comprised of poly(allylamine) and poly(acrylic) acid, with further uptake of palladium ions from aqueous solution and electrochemical reduction under potentiostatic control. The as-prepared electrodes have been characterized by XPS, SEM and cyclic voltammetry and the palladium content was determined by ICP elemental analysis. Furthermore, the nanoelectrocatalyst has been assessed by studying the electrochemical hydrogenation of acetophenone2 as a model compound. Both, SEM images (see figure) and XPS show that the electrochemically generated Pd nanoparticles are preferentially located at the electrode/film interface, in contrast with the homogeneous distribution observed when a chemical reduction route is used1. Cyclic voltammetry shows the typical response of a polycrystalline Pd electrode3. The anodic hydrogen peak is completely suppressed in the presence of acetophenone which confirms the electrocatalytic activity. These properties were tested in batch process and followed by HPLC. Complete reduction of acetophenone to ethyl benzene with a current efficiency of 84% has been observed. In addition, the electrocatalytic performance was compared with that of an electrode bearing Pd microcrystals prepared by direct electroreduction of Pd(II) salts2,3 on the carbon surface resulting in a reduction rate per mole of Pd ten-fold faster than for the microcrystalline Pd electrode prepared by the standard method (1) Joly, S.; Kane, R.; Radzilowski, L.; Wang, T.; Wu, A.; Cohen, R. E.; Thomas, E. L.; Rubner, M. F. Langmuir 2000, 16, 1354. (2) Polcaro, A.; Palmas, S.; Dernini, S. Ind. Eng. Chem. Res. 1993, 32, 1315. (3) Pattabiraman, R., Applied Catalysis A. 1997, 153, 9.1 comprised of poly(allylamine) and poly(acrylic) acid, with further uptake of palladium ions from aqueous solution and electrochemical reduction under potentiostatic control. The as-prepared electrodes have been characterized by XPS, SEM and cyclic voltammetry and the palladium content was determined by ICP elemental analysis. Furthermore, the nanoelectrocatalyst has been assessed by studying the electrochemical hydrogenation of acetophenone2 as a model compound. Both, SEM images (see figure) and XPS show that the electrochemically generated Pd nanoparticles are preferentially located at the electrode/film interface, in contrast with the homogeneous distribution observed when a chemical reduction route is used1. Cyclic voltammetry shows the typical response of a polycrystalline Pd electrode3. The anodic hydrogen peak is completely suppressed in the presence of acetophenone which confirms the electrocatalytic activity. These properties were tested in batch process and followed by HPLC. Complete reduction of acetophenone to ethyl benzene with a current efficiency of 84% has been observed. In addition, the electrocatalytic performance was compared with that of an electrode bearing Pd microcrystals prepared by direct electroreduction of Pd(II) salts2,3 on the carbon surface resulting in a reduction rate per mole of Pd ten-fold faster than for the microcrystalline Pd electrode prepared by the standard method (1) Joly, S.; Kane, R.; Radzilowski, L.; Wang, T.; Wu, A.; Cohen, R. E.; Thomas, E. L.; Rubner, M. F. Langmuir 2000, 16, 1354. (2) Polcaro, A.; Palmas, S.; Dernini, S. Ind. Eng. Chem. Res. 1993, 32, 1315. (3) Pattabiraman, R., Applied Catalysis A. 1997, 153, 9.2 as a model compound. Both, SEM images (see figure) and XPS show that the electrochemically generated Pd nanoparticles are preferentially located at the electrode/film interface, in contrast with the homogeneous distribution observed when a chemical reduction route is used1. Cyclic voltammetry shows the typical response of a polycrystalline Pd electrode3. The anodic hydrogen peak is completely suppressed in the presence of acetophenone which confirms the electrocatalytic activity. These properties were tested in batch process and followed by HPLC. Complete reduction of acetophenone to ethyl benzene with a current efficiency of 84% has been observed. In addition, the electrocatalytic performance was compared with that of an electrode bearing Pd microcrystals prepared by direct electroreduction of Pd(II) salts2,3 on the carbon surface resulting in a reduction rate per mole of Pd ten-fold faster than for the microcrystalline Pd electrode prepared by the standard method (1) Joly, S.; Kane, R.; Radzilowski, L.; Wang, T.; Wu, A.; Cohen, R. E.; Thomas, E. L.; Rubner, M. F. Langmuir 2000, 16, 1354. (2) Polcaro, A.; Palmas, S.; Dernini, S. Ind. Eng. Chem. Res. 1993, 32, 1315. (3) Pattabiraman, R., Applied Catalysis A. 1997, 153, 9.1. Cyclic voltammetry shows the typical response of a polycrystalline Pd electrode3. The anodic hydrogen peak is completely suppressed in the presence of acetophenone which confirms the electrocatalytic activity. These properties were tested in batch process and followed by HPLC. Complete reduction of acetophenone to ethyl benzene with a current efficiency of 84% has been observed. In addition, the electrocatalytic performance was compared with that of an electrode bearing Pd microcrystals prepared by direct electroreduction of Pd(II) salts2,3 on the carbon surface resulting in a reduction rate per mole of Pd ten-fold faster than for the microcrystalline Pd electrode prepared by the standard method (1) Joly, S.; Kane, R.; Radzilowski, L.; Wang, T.; Wu, A.; Cohen, R. E.; Thomas, E. L.; Rubner, M. F. Langmuir 2000, 16, 1354. (2) Polcaro, A.; Palmas, S.; Dernini, S. Ind. Eng. Chem. Res. 1993, 32, 1315. (3) Pattabiraman, R., Applied Catalysis A. 1997, 153, 9.3. The anodic hydrogen peak is completely suppressed in the presence of acetophenone which confirms the electrocatalytic activity. These properties were tested in batch process and followed by HPLC. Complete reduction of acetophenone to ethyl benzene with a current efficiency of 84% has been observed. In addition, the electrocatalytic performance was compared with that of an electrode bearing Pd microcrystals prepared by direct electroreduction of Pd(II) salts2,3 on the carbon surface resulting in a reduction rate per mole of Pd ten-fold faster than for the microcrystalline Pd electrode prepared by the standard method (1) Joly, S.; Kane, R.; Radzilowski, L.; Wang, T.; Wu, A.; Cohen, R. E.; Thomas, E. L.; Rubner, M. F. Langmuir 2000, 16, 1354. (2) Polcaro, A.; Palmas, S.; Dernini, S. Ind. Eng. Chem. Res. 1993, 32, 1315. (3) Pattabiraman, R., Applied Catalysis A. 1997, 153, 9.2,3 on the carbon surface resulting in a reduction rate per mole of Pd ten-fold faster than for the microcrystalline Pd electrode prepared by the standard method (1) Joly, S.; Kane, R.; Radzilowski, L.; Wang, T.; Wu, A.; Cohen, R. E.; Thomas, E. L.; Rubner, M. F. Langmuir 2000, 16, 1354. (2) Polcaro, A.; Palmas, S.; Dernini, S. Ind. Eng. Chem. Res. 1993, 32, 1315. (3) Pattabiraman, R., Applied Catalysis A. 1997, 153, 9.Langmuir 2000, 16, 1354. (2) Polcaro, A.; Palmas, S.; Dernini, S. Ind. Eng. Chem. Res. 1993, 32, 1315. (3) Pattabiraman, R., Applied Catalysis A. 1997, 153, 9.Ind. Eng. Chem. Res. 1993, 32, 1315. (3) Pattabiraman, R., Applied Catalysis A. 1997, 153, 9.Applied Catalysis A. 1997, 153, 9.