The growing demand for high performance from supercapacitors has inspired the development of porous nanocomposites using renewable and naturally available materials. In this work, a formaldehyde-free phenolic resin using monosaccharide-based furfural was synthesized to act as the carbon precursor. One dimensional halloysite nanotube (HNT) with high porosity and excellent cation/anion exchange capacity was mixed with the phenol-furfural resin to fabricate carbonaceous nanocomposite HNT/C. Their structure and porosity were characterized. The effects of the halloysite nanotube amount and carbonization temperature on the electrochemical properties of HNT/C were explored. HNT/C exhibited rich porosity, involving a large specific surface area 253 m²·g⁻¹ with a total pore volume of 0.27 cm³·g⁻¹. The electrochemical performance of HNT/C was characterized in the three-electrode system and showed enhanced specific capacitance of 146 F·g⁻¹ at 0.2 A g⁻¹ (68 F·g⁻¹ for pristine carbon) in electrolyte (6 mol·L⁻¹ KOH) and a good rate capability of 62% at 3 A g⁻¹. It also displayed excellent cycle performance with capacitance retention of 98.5% after 500 cycles. The symmetric supercapacitors with HNT/C-1:1.5-800 electrodes were fabricated, exhibiting a high energy density of 20.28 Wh·Kg⁻¹ at a power density of 100 W·Kg⁻¹ in 1 M Na₂SO₄ electrolyte. The present work provides a feasible method for preparing composite electrode materials with a porous structure from renewable phenol-furfural resin and HNT. The excellent supercapacitance highlights the potential applications of HNT/C in energy storage.

In the study presented herein, a series of TiO₂-supported Ru catalysts were prepared through over-impregnation with different amounts of H₂O₂ and applied to the catalytic combustion of dichloromethane (DCM). The experimental results show that the optimal (1 H₂O₂)-Ru@TiO₂ catalyst sample yields 90% DCM conversion at 301 °C, which is 40 °C lower than the temperature required by the (0 H₂O₂)-Ru@TiO₂ catalyst. This good activity is related to its high number of acid sites (especially Brønsted acid sites), an appropriate amount of uniformly dispersed RuO₂ particles, and strong interaction between RuO₂ and the TiO₂ support. In addition, excessive H₂O₂ leads to the growth and phase segregation of RuO₂, which weakens the interaction between RuO₂ and the TiO₂ support and decreases catalytic activity. Moreover, H₂O₂ addition also contributes to the stability of catalysts, which possibly results from the re-dispersion of RuO₂ on the TiO₂ support during the reaction.