Processibility and biodegradability of conductive polymers are major concerns when they are applied to tissue regeneration. This study synthesizes dissolvable and conductive aniline trimer-based polyurethane copolymers (DCPU) and processes them into scaffolds by using electrospinning with different patterns (random, oriented, and latticed). The effects of topographic cue changes on electrical signal transmission and further regulation of cell behaviors concerning bone tissue are researched. Results show that DCPU fibrous scaffolds possessed good hydrophilicity, swelling capacity, elasticity, and fast biodegradability in enzymatic liquid. In addition, the conductivity and efficiency of electrical signal transmission can be tuned by changing the surface’s topological structure. Among them, oriented DCPU scaffolds (DCPU-O) showed the best conductivity with the lowest ionic resistance value. Furthermore, the viability and proliferation results of bone mesenchymal stem cells (BMSCs) demonstrate a significant increase on three DCPU scaffolds compared to AT-free scaffolds (DPU-R). Especially, DCPU-O scaffolds exhibit superior abilities to promote cell proliferation because of their unique surface topography and excellent electroactivity. Concurrently, the DCPU-O scaffolds can synergistically promote osteogenic differentiation in terms of osteogenic differentiation and gene expression levels when combined with electrical stimulation. Together, these results suggest a promising use of DCPU-O fibrous scaffolds in the application of tissue regeneration.

A series of Ni-xSi/ZrO₂ (x = 0, 0.1, 0.5, 1 wt%, the controlled contents of Si) catalysts with a controlled nickel content of 10 wt% were prepared by the co-impregnation method with ZrO₂ as support and Si as a promoter. The effect of different amounts of Si on the catalytic performance was investigated for CO₂ methanation with the stoichiometric H₂/CO₂ molar ratio (4/1). The catalysts were characterized by BET, XRF, H₂-TPR, H₂-TPD, H₂-chemisorption, CO₂-TPD, XRD, TEM, XPS, and TG-DSC. It was found that adding the appropriate amount of Si could improve the catalytic performance of Ni/ZrO₂ catalyst at a low reaction temperature (250 °C). Among all the catalysts studied, the Ni-0.1Si/ZrO₂ catalyst showed the highest catalytic activity, with H₂ and CO₂ conversion of 73.4% and 72.5%, respectively and the yield of CH₄ was 72.2%. Meanwhile, the catalyst showed high stability and no deactivation within a 10 h test. Adding the appropriate amount of Si could enhance the interaction between Ni and ZrO₂, and increase the Ni dispersion, the amounts of active sites including surface Ni⁰, oxygen vacancies, and strong basic sites on the catalyst surface. These might be the reasons for the high activity and selectivity of the Ni-0.1Si/ZrO₂ catalyst.

Ni-based catalysts (Ni-γ-Al₂O₃, Ni-HTASO5 and Ni-CeZrO_x) were prepared by impregnation method and characterized by BET, AAS, XRD, H₂-TPR, CO-TPD, NH₃-TPD, XPS, TG-DSC-MS and Raman spectroscopies. Using CeZrO_x-modified Al₂O₃ (HTASO5) as support, the catalyst exhibited good catalytic performance (TOF_CH4 = 8.0 × 10⁻² s⁻¹, TOF_H2 = 10.5 × 10⁻² s⁻¹) and carbon resistance for steam-methane reforming (SMR) reaction. Moreover, CeZrO_x was able to enhance water-gas shift (WGS) reaction for more hydrogen production. It was found that the addition of CeZrO_x could increase the content of active nickel precursor on the surface of the catalyst, which was beneficial to the decomposition of water and methane on Ni-HTASO5. Furthermore, Ni-HTASO5 could decrease the strong acid sites of the catalyst, which would not only contribute to the formation of low graphited carbon, but also decrease the amount of carbon deposition.