船用907钢表面化学镀耐冲刷腐蚀型NiMoB合金层的工艺参数优化

为提高船用907钢的耐冲刷腐蚀性能,设计了一种可与船用907钢海水管路内壁表面形成稳定化合物的NiMoB合金镀层,并采用正交试验优选了该化学镀液中NiCl_2,EDTA,Na_2MoO_4,KBH_4的浓度。采用扫描电镜观察合金镀层形貌;采用阻抗谱、极化曲线分析了合金镀层在模拟海水中的耐蚀性,并在模拟海水冲刷腐蚀环境下分析了Ni Mo B镀层的抗冲刷腐蚀特性。结果表明:不同的镀液参数对Ni Mo B镀层的性能影响较大,当NiCl_245.0g/L、EDTA 9.0 g/L、Na_2MoO_415.0 g/L、KBH_40.8 g/L,乙二胺45.0 g/L,NaOH 90.0 g/L时,NiMoB非晶态薄膜表面呈胞状物陈列,具有致密的表面形貌,镀层的耐腐蚀、抗冲刷腐蚀性能优良。     

Catalytic Hydrogenation for Bio‐Oil Upgrading by a Supported NiMoB Amorphous Alloy

A method of ultrasound‐assisted reduction of a nickel‐ammonia complex with borohydride in aqueous solution was used to prepare NiMoB/MCM‐41 and NiMoB/SBA‐15 supported amorphous alloy catalysts. These catalysts were used to upgrade bio‐oil at mild temperatures ranging from 100 to 160 °C and recycling of these two supported catalysts and of unsupported NiMoB was carried out. Then, fresh and third time used catalysts were characterized by X‐ray diffraction, X‐ray photoelectron spectra, and transmission electron microscopy. Quantitative results were obtained from the analysis of gas chromatography/mass spectrometry. Through mild upgrading, 1‐hydroxy‐2‐propanone, furfural, and 2‐methoxy‐4‐vinylphenol in the bio‐oil were converted to relevant alcohols and saturated phenols. The conversion rates were 45.7, 71.5, and 57.1 %, respectively, when crude bio‐oil was upgraded using NiMoB/MCM‐41 at 160 °C. The two supported catalysts, especially NiMoB/MCM‐41, had smaller amorphous NiMoB particles and exhibited more uniform dispersion on mesoporous silica, leading to higher reaction activity and stability than unsupported NiMoB. Deactivation of these catalysts resulted from the reduction of Ni⁰, B⁰, and Mo⁴⁺ species on the surface, the transition from the amorphous to the crystalline state, particle agglomeration, and coke deposition on the surface.