Construction of stable Mo_xS_y/CeO₂ heterostructures for the electrocatalytic hydrogen evolution reaction

Abstract

The unique structures of polynuclear MoxSy clusters make them maximize the number of active sites, being good candidates as HER catalysts. An appropriate support is highly necessary not only to...

CeO2-supported multi-nuclear NbxSy clusters for hydrogen evolution reaction

“…1), including Nb 3 S 4 , Nb 4 S 3 , and Nb 4 S 4 clusters. 29 Three Nb atoms of incomplete cubane-type Nb 3 S 4 clusters constructed an isosceles triangle with an average bond length ( l Nb–Nb ) of 2.57 Å, and the coordination structures of S atoms included three doubly bridging sulfurs (μ 2 -S) and one triply-bridging sulfur (μ 3 -S), where the average value of l Nb–(μ 2 -S) and l Nb–(μ 3 -S) were 2.37 Å and 2.45 Å, respectively. The Nb atoms of Nb 4 S 3 formed a regular triangular pyramid coordinated with three μ 2 -S, and the skeleton structure of Nb 4 S 4 was an Nb 4 tetrahedron with four μ 3 -S. The values of the bottom and side l Nb–Nb on Nb 4 S 3 were 2.61 Å and 2.68 Å, respectively, and the l Nb–Nb of Nb 4 S 4 was shorter with a value of 2.58 Å.…”

“…The Bader charge transfer (Dq) from Nb 3 S 4 , Nb 4 S 3 , and Nb 4 S 4 to CeO 2 supports are 1.29e, 1.55e, and 1.09e, respectively, which means that these Nb x S y clusters are positively charged, accompanying the reduction of some Ce atoms from Ce 4+ to Ce 3+ . 29 From the Bader charge shown in Table S2, † we can see that the reduced Ce 3+ cations are negatively charged with ∼0.30e compared with the inner-layer Ce 4+ , showing the injection of the electrons to these reduced Ce 3+ cations. Compared with 0 m B of Ce 4+ , the Ce-4f orbitals of the reduced Ce 3+ cations would present a magnetic moment of ∼1 m B due to the electron injection (Table S2 †).…”

“…25 The reactivities of the gas-phase NbS + cation with some small molecules, such as CO and CO 2 have been investigated, 26–28 and several bi-nuclear complexes containing Nb 2 S 4 4+ cores have been reported as precatalysts in the reaction of HER. Compared to the relatively less attention paid to Nb x S y clusters gained in HER, Mo x S y clusters have been widely used as promising HER catalysts, 29 such as Mo 2 S 12 , 30 Mo 3 S 4 , 31–35 Mo 3 S 7 , 36,37 Mo 3 S 13 , 38–41 and Mo 6 S 8 . 42 The current research on Nb x S y clusters mainly focuses on the mono/bi-nuclear Nb x S y clusters in the gas phase, and multi-nuclear Nb x S y clusters are rarely reported, especially in the HER study.…”

“…29 such as Mo 2 S 12 , 30 Mo 3 S 4 ,[31][32][33][34][35] Mo 3 S 7 , 36,37 Mo 3 S 13 ,[38][39][40][41] and Mo 6 S 8 .…”

Rare earth oxide based electrocatalysts: synthesis, properties and applications

“…The research by Zhang et al showed that CeO 2 support can provide strong support for the interaction of various Mo x S y clusters, and the formed Mo x S y /CeO 2 heterostructures also have moderate Δ G H* for the HER. 107 The electronic properties of Mo x S y clusters are regulated by CeO 2 carriers, which cause charge redistribution on the edge atoms and play a key role in H adsorption. This study provides guidance for the prediction of highly effective candidate MoS 2 based catalysts for the HER.…”