贵金属
貴金屬
귀금속
PRECIOUS METALS
2009年
1期
26-33
,共8页
张振强%桓源峰%贺小昆%赵云昆
張振彊%桓源峰%賀小昆%趙雲昆
장진강%환원봉%하소곤%조운곤
物理化学%金属载体%表面预处理%涂层%拟薄水铝石%结合性能
物理化學%金屬載體%錶麵預處理%塗層%擬薄水鋁石%結閤性能
물이화학%금속재체%표면예처리%도층%의박수려석%결합성능
physical chemistry%metallic substrate%surface pretreatment%coating layer%pseudobohemite%combination performance
随着冷启动排放问题的日益严重,金属载体催化剂除了应用于摩托车和柴油机尾气催化燃烧外,不久将用于密耦型催化剂.然而,金属载体与活性涂层之间低的粘结力是制约金属载体催化剂发展的瓶颈.该文报导了一个3步工序:碱蚀预处理→950 ℃氧化→浸渍涂层并焙烧.超声波振动和高温急冷后超声波振动分别用于测定活性涂层的脱落率.结果表明,整体型金属载体起始负载达到10%,在经超声波振动后,脱落率为1.4%.与此同时,还发现经碱蚀后的FeCrAl合金表面存在许多大小不一的"坑".这些"坑"为后续的活性涂层起到钉扎作用.XRD分析可知,Fe-Cr固熔体在氧化层下面富集.SEM图象表明,煅烧后致密的氧化铝层在活性涂层和FeCrAl合金的界面形成,这极大地有益于增强活性γ-Al2O3涂层在FeCrAl合金箔材上的粘结力.
隨著冷啟動排放問題的日益嚴重,金屬載體催化劑除瞭應用于摩託車和柴油機尾氣催化燃燒外,不久將用于密耦型催化劑.然而,金屬載體與活性塗層之間低的粘結力是製約金屬載體催化劑髮展的瓶頸.該文報導瞭一箇3步工序:堿蝕預處理→950 ℃氧化→浸漬塗層併焙燒.超聲波振動和高溫急冷後超聲波振動分彆用于測定活性塗層的脫落率.結果錶明,整體型金屬載體起始負載達到10%,在經超聲波振動後,脫落率為1.4%.與此同時,還髮現經堿蝕後的FeCrAl閤金錶麵存在許多大小不一的"坑".這些"坑"為後續的活性塗層起到釘扎作用.XRD分析可知,Fe-Cr固鎔體在氧化層下麵富集.SEM圖象錶明,煅燒後緻密的氧化鋁層在活性塗層和FeCrAl閤金的界麵形成,這極大地有益于增彊活性γ-Al2O3塗層在FeCrAl閤金箔材上的粘結力.
수착랭계동배방문제적일익엄중,금속재체최화제제료응용우마탁차화시유궤미기최화연소외,불구장용우밀우형최화제.연이,금속재체여활성도층지간저적점결력시제약금속재체최화제발전적병경.해문보도료일개3보공서:감식예처리→950 ℃양화→침지도층병배소.초성파진동화고온급랭후초성파진동분별용우측정활성도층적탈락솔.결과표명,정체형금속재체기시부재체도10%,재경초성파진동후,탈락솔위1.4%.여차동시,환발현경감식후적FeCrAl합금표면존재허다대소불일적"갱".저사"갱"위후속적활성도층기도정찰작용.XRD분석가지,Fe-Cr고용체재양화층하면부집.SEM도상표명,단소후치밀적양화려층재활성도층화FeCrAl합금적계면형성,저겁대지유익우증강활성γ-Al2O3도층재FeCrAl합금박재상적점결력.
With increasing seriously problem of cold-start emission, metallic substrate catalyst, besides applied to catalytic combustion of motorcycle and diesel exhaust, will be also served as closed-coupled catalyst in the future. However, lower adhesion between metallic substrates and washcoat is the bottleneck problem restricting metallic substrate catalyst to develop. The paper reports a three-step procedure: alkali-etching pretreatment→oxidation at 950 ℃→coating impregnation and calcination. Ultrasonic vibration and ultrasonic vibration after quenching from high temperature tests were taken to examine weight loss of washcoat, respectively. The results showed that, initiative loading weight of monolithic metallic substrate reaches 10 wt%, and weight loss after ultrasonic vibration test is 1.4 wt%. Meanwhile, we also found that, in surface of FeCrAl alloy after etching pretreatment, there are many "pits" with different sizes which serves as pinning action for the loading washcoat. XRD analysis indicated that Fe-Cr solid solution concentrats under the oxide layer of FeCrAl alloy. SEM images indicated that after calcined, dense alumina layer forms at the interface between washcoat and FeCrAl alloy, which is greatly favourable to enhance the adhesion of the active γ-Al2O3 coating to FeCrAl foil material.