TY - JOUR
T1 - Effect of Cations on the Structure and Electrocatalytic Response of Polyoxometalate-Based Coordination Polymers
AU - Salomon, William
AU - Paille, Grégoire
AU - Gomez-Mingot, Maria
AU - Mialane, Pierre
AU - Marrot, Jérôme
AU - Roch-Marchal, Catherine
AU - Nocton, Gregory
AU - Mellot-Draznieks, Caroline
AU - Fontecave, Marc
AU - Dolbecq, Anne
N1 - Publisher Copyright:
© 2017 American Chemical Society.
PY - 2017/4/5
Y1 - 2017/4/5
N2 - A series of six hybrid polymers based on the mixed-valent {ϵ-PMoV8MoVI4O40Zn4} (ϵZn) Keggin unit have been synthesized under hydrothermal conditions using tritopic (1,3,5-benzenetricarboxylate (trim) or 1,3,5-benzenetribenzoate (BTB)) or ditopic (4,4′-biphenyldicarboxylate (biphen)) linkers and [M(bpy)3]2+ (M = Co, Ru) complexes as charge-compensating cations. (TBA)2[Co(C10H8N2)3][PMo12O37(OH)3Zn4](C27H15O6)4/3·1.5C27H18O6·24H2O (Co-ϵ(BTB)4/3) has a three-dimensional (3D) framework with two interpenetrated networks and is isostructural to (TBA)4[PMo12O37(OH)3Zn4](C27H15O6)4/3·1.5C27H18O6·8H2O (ϵ(BTB)4/3). In Co-ϵ(BTB)4/3, two tetrabutylammonium (TBA+) cations over the four present in ϵ(BTB)4/3 are replaced by one [Co(bpy)3]2+ complex. [Co(C10H8N2)3][PMo12O37(OH)3Zn4](C9H3O6)Co(C10H8N2)4(H2O)·16H2O (Co-ϵ(trim) (bpy)2) is a 1D coordination polymer with two types of CoII-containing complexes, one covalently attached to the 1D chains and the other located in the voids as the counterion. [Ru(C10H8N2)3]4[PMo12O38(OH)2Zn4]2(C9H3O6)2·42H2O (Ru-ϵ2(trim)2) and [Ru(C10H8N2)3]3[PMo12O37(OH)3Zn4Cl]2(C14H8O4)2·24H2O (Ru-ϵ2(biphen)2) contain dimeric (ϵZn)2 units linked by dicarboxylate linkers, and both have [Ru(bpy)3]2+ countercations. Ru-ϵ2(trim)2 has a 3D framework, while Ru-ϵ2(biphen)2 is only 2D because of the presence of chloride ions on one-fourth of the ZnII ions. [P(C6H5)4]6[PMo12O37(OH)3Zn4]2(C9H3O6)2·18H2O (PPh4-ϵ2(trim)2) is isostructural to Ru-ϵ2(trim)2. These insoluble compounds entrapped in carbon-paste electrodes exhibit electrocatalytic activity for the hydrogen evolution reaction. The effects of their structure and the nature of the counterions on the activity have been studied. For the first time, different POM-based coordination polymers are compared for catalytic H2 production using controlled-potential electrolysis. This study shows that the nature of the countercation has a strong effect on the electrocatalytic activity of the compound.
AB - A series of six hybrid polymers based on the mixed-valent {ϵ-PMoV8MoVI4O40Zn4} (ϵZn) Keggin unit have been synthesized under hydrothermal conditions using tritopic (1,3,5-benzenetricarboxylate (trim) or 1,3,5-benzenetribenzoate (BTB)) or ditopic (4,4′-biphenyldicarboxylate (biphen)) linkers and [M(bpy)3]2+ (M = Co, Ru) complexes as charge-compensating cations. (TBA)2[Co(C10H8N2)3][PMo12O37(OH)3Zn4](C27H15O6)4/3·1.5C27H18O6·24H2O (Co-ϵ(BTB)4/3) has a three-dimensional (3D) framework with two interpenetrated networks and is isostructural to (TBA)4[PMo12O37(OH)3Zn4](C27H15O6)4/3·1.5C27H18O6·8H2O (ϵ(BTB)4/3). In Co-ϵ(BTB)4/3, two tetrabutylammonium (TBA+) cations over the four present in ϵ(BTB)4/3 are replaced by one [Co(bpy)3]2+ complex. [Co(C10H8N2)3][PMo12O37(OH)3Zn4](C9H3O6)Co(C10H8N2)4(H2O)·16H2O (Co-ϵ(trim) (bpy)2) is a 1D coordination polymer with two types of CoII-containing complexes, one covalently attached to the 1D chains and the other located in the voids as the counterion. [Ru(C10H8N2)3]4[PMo12O38(OH)2Zn4]2(C9H3O6)2·42H2O (Ru-ϵ2(trim)2) and [Ru(C10H8N2)3]3[PMo12O37(OH)3Zn4Cl]2(C14H8O4)2·24H2O (Ru-ϵ2(biphen)2) contain dimeric (ϵZn)2 units linked by dicarboxylate linkers, and both have [Ru(bpy)3]2+ countercations. Ru-ϵ2(trim)2 has a 3D framework, while Ru-ϵ2(biphen)2 is only 2D because of the presence of chloride ions on one-fourth of the ZnII ions. [P(C6H5)4]6[PMo12O37(OH)3Zn4]2(C9H3O6)2·18H2O (PPh4-ϵ2(trim)2) is isostructural to Ru-ϵ2(trim)2. These insoluble compounds entrapped in carbon-paste electrodes exhibit electrocatalytic activity for the hydrogen evolution reaction. The effects of their structure and the nature of the counterions on the activity have been studied. For the first time, different POM-based coordination polymers are compared for catalytic H2 production using controlled-potential electrolysis. This study shows that the nature of the countercation has a strong effect on the electrocatalytic activity of the compound.
U2 - 10.1021/acs.cgd.6b01600
DO - 10.1021/acs.cgd.6b01600
M3 - Article
AN - SCOPUS:85017119179
SN - 1528-7483
VL - 17
SP - 1600
EP - 1609
JO - Crystal Growth and Design
JF - Crystal Growth and Design
IS - 4
ER -