A TiO2/Nb2O5·nH2O heterojunction catalyst for conversion of glucose into 5-hydroxymethylfurfural in water

A series of water-tolerant Lewis acidic TiO₂/Nb₂O₅·nH₂O heterojunction catalysts with different Ti : Nb ratios have been prepared and investigated in the conversion of glucose into HMF in water.

On the influence of the titanium source on the composition and structure of novel titanoniobates

Systematic variation of the titanium source and the reaction temperature applied during hydrothermal synthesis led to crystallization of four new titanoniobates: {[Ni(cyclam)]₄[Ti₂Nb₈O₂₈]}_n·∼28nH₂O (I), K[Ni(cyclam)]₃[TiNb₉O₂₈]·xH₂O; x = 18 (II), x = 14 (III) and x ∼ 10(IV).

Two Rh(III)-substituted polyoxoniobates and their base-induced transformation: [H2RhNb9O28](6-) and [Rh2(OH)4Nb10O30](8-)

Two new rhodium-substituted polyoxoniobates, [H2RhNb9O28](6-) (RhNb9) and [Rh2(OH)4Nb10O30](8-) (Rh2Nb10) are reported. The two distinct Rh(III)-substituted niobate clusters behave differently when the pH is raised with TMAOH: the Rh2Nb10 is stable until pH ∼ 12.7, but RhNb9 dissociates to form RhNb5 and RhNb10, similar to some of our other metal-substituted niobates, such as the MNb9 ions (M = Cr or Mn), which transform to MNb10 when the solution pH is raised.