本文選題：電沉積 + 銀基催化劑��； 參考：《太原理工大學(xué)》2017年碩士論文

【摘要】：日益嚴(yán)重的環(huán)境問(wèn)題和化石燃料能源危機(jī),使來(lái)源豐富、清潔、可再生的氫氣逐漸成為最有前景的替代能源之一。電解水制氫是技術(shù)發(fā)展比較成熟的一種制氫方式,其優(yōu)點(diǎn)在于工藝過(guò)程簡(jiǎn)單、操作方便、產(chǎn)物純凈無(wú)污染。但電解水制氫技術(shù)存在著成本高、能耗大、能源轉(zhuǎn)化效率低等問(wèn)題,限制了其工業(yè)化發(fā)展。因此制備高效的水裂解催化劑是電解水制氫技術(shù)的關(guān)鍵。目前Ag基催化劑用于陽(yáng)極水氧化析氧反應(yīng)已有報(bào)道,Ag析氧催化劑具有析氧過(guò)電勢(shì)低、結(jié)構(gòu)易于調(diào)變的優(yōu)點(diǎn),但是其電流密度相對(duì)較低。而低過(guò)電勢(shì)和高電流密度是高效析氧電催化的重要參數(shù),對(duì)銀基析氧催化劑進(jìn)行結(jié)構(gòu)設(shè)計(jì)和改性,可進(jìn)一步降低能耗和提高效率。本文采用原位電沉積的方法對(duì)Ag基催化劑從形貌、晶面和金屬氧化物復(fù)合三個(gè)方面進(jìn)行了改性設(shè)計(jì),通過(guò)XRD、SEM、EDS、XPS等表征手段對(duì)其結(jié)構(gòu)、形貌、組成及價(jià)態(tài)進(jìn)行分析,并通過(guò)循環(huán)伏安法、線(xiàn)性?huà)呙璺卜ā⒑汶娢环▽?duì)Ag基催化劑的電催化性能進(jìn)行測(cè)試。具體研究?jī)?nèi)容主要分為以下三個(gè)部分:1.在乙酸鉀中原位加入氨水作為電解質(zhì)體系,以硝酸銀為前驅(qū)體,采用原位恒電位沉積法制備了銀基析氧催化劑薄膜。通過(guò)原位加入絡(luò)合劑NH_3H_2O的方式,既能改變?nèi)芤核釅A度,又不造成Ag~+因與OH~-的鍵合作用而在溶液中的損失,還能改變Ag+在溶液中的金屬存在形態(tài),進(jìn)而影響其陽(yáng)極的沉積態(tài)。通過(guò)系列表征確定其活性組分為AgO。隨著氨水加入量的調(diào)變,所得到的銀基催化劑的形貌不同,進(jìn)而影響其析氧催化性能,在氨水加入量與溶液中的Ag+完全絡(luò)合且氨無(wú)過(guò)量時(shí),所得到的Ag基催化劑催化水氧化性能最高。2.在硝酸鉀中原位加入氨水作為電解質(zhì)體系,以硝酸銀為前驅(qū)體,通過(guò)原位恒電位沉積法制備銀基析氧催化劑薄膜。選擇硝酸鉀為電解質(zhì),一方面在乙酸鉀的基礎(chǔ)上進(jìn)一步減小電解質(zhì)陰離子與Ag+的鍵合作用;另外舍棄了傳統(tǒng)的緩沖溶液電解質(zhì)作為質(zhì)子載體的觀念,利用絡(luò)合劑NH3作為質(zhì)子載體。研究結(jié)果表明其催化劑的活性組分仍為AgO,但隨著氨水加入量的增加,所得到的銀基催化劑的晶面發(fā)生了變化,逐漸從以AgO(202)面為主峰變?yōu)橐?Ⅲ)面為主峰,并且在以(Ⅲ)為主峰時(shí)所得到的銀基催化劑其催化水氧化性能較好。通過(guò)理論計(jì)算得到在堿性環(huán)境中AgO(Ⅲ)面是最穩(wěn)定存在的晶面,且其在堿性環(huán)境中對(duì)OH-的氧化性能最佳,與實(shí)驗(yàn)數(shù)據(jù)相吻合。3.在硝酸鈷中原位加入氨水作為電解質(zhì)體系,以硝酸銀為前驅(qū)體,利用原位恒電位沉積法成功制備了鈷銀雙金屬氧化物析氧催化劑薄膜。選擇硝酸鈷為電解質(zhì),在減小電解質(zhì)陰離子與Ag~+的鍵合作用的基礎(chǔ)上,利用Co~(2+)、Ag~+都能和NH3絡(luò)合的性質(zhì),在陽(yáng)極共沉積形成鈷銀雙金屬氧化物。通過(guò)實(shí)驗(yàn)發(fā)現(xiàn)當(dāng)NH3加入量為150μL,沉積量為~1C時(shí),其析氧催化性能最佳,研究表明其活性組分為鈷銀雙金屬氧化物,且為鈷銀協(xié)同催化。
[Abstract]:The increasingly serious environmental problems and the fossil fuel energy crisis make the rich, clean and renewable hydrogen gradually become one of the most promising alternative energy sources. Electrolysis water is a relatively mature technology for hydrogen production. Its advantages lie in simple process, easy operation and pure products without pollution. There are many problems such as high cost, high energy consumption and low efficiency of energy conversion, which restrict the development of its industrialization. Therefore, the key to the preparation of high efficient water cracking catalyst is the technology of electrolyzing water for hydrogen production. At present, the Ag based catalyst has been reported in the anodic oxygen evolution reaction of the anode. The Ag oxygen evolution catalyst has the advantages of low oxygen evolution potential and easy to adjust the structure. But its current density is relatively low. The low overpotential and high current density are the important parameters of high efficiency oxygen evolution electrocatalysis. The structure design and modification of the silver based oxygen evolution catalyst can further reduce energy consumption and improve efficiency. In this paper, the Ag based catalyst is composed of three compounds from the morphology, the crystal surface and the metal oxide. The modified design was carried out, and its structure, morphology, composition and valence state were analyzed by means of XRD, SEM, EDS and XPS. The electrocatalytic properties of Ag based catalysts were tested by cyclic voltammetry, linear sweep voltammetry and potentiostatic method. The main contents are divided into three parts: 1. in situ addition of potassium acetate As the electrolyte system and the silver nitrate as the precursor, the silver based oxygen evolution catalyst film was prepared by in situ potentiostatic deposition. By adding the complexing agent NH_3H_2O in situ, the solution can not only change the pH of the solution, but also do not cause the loss of the Ag~+ in the solution because of the cooperation with the OH~-, but also change the metal storage of the Ag+ in the solution. In the form, it affects the deposition of the anode. Through a series of characterization, it is determined that the active component is AgO. with the adjustment of the amount of ammonia water. The morphology of the silver based catalyst is different, and then it affects the catalytic performance of oxygen evolution. The Ag based catalyst is catalyzed by the Ag based catalyst when the amount of ammonia is added to the Ag+ in the solution and the ammonia is not overdose. The water oxidation performance is the highest.2. in the potassium nitrate in situ adding ammonia water as the electrolyte system. Silver nitrate is used as the precursor to prepare the silver based oxygen evolution catalyst film by in situ potentiostatic deposition. The potassium nitrate is selected as the electrolyte. On the one hand, the bonding effect of the electrosolution anion and the Ag+ is further reduced on the basis of potassium acetate; in addition, it is abandoned. The traditional buffer solution electrolyte is a proton carrier, using the complexing agent NH3 as a proton carrier. The results show that the active component of the catalyst is still AgO, but with the increase of the amount of ammonia water, the crystal surface of the obtained silver base catalyst changes from the main peak of the AgO (202) surface to the main peak of the (III) surface. The AgO (III) surface is the most stable crystal surface in the alkaline environment, and the oxidation performance of OH- in alkaline environment is the best. In accordance with the experimental data,.3. is in situ added to the cobalt nitrate as the electrolyte system. With silver nitrate as precursor, cobalt and silver bimetallic oxide oxide catalyst film was prepared by in situ potentiostatic deposition. Cobalt nitrate was selected as electrolyte. On the basis of reducing the bond of electrolyte anion and Ag~+, Co~ (2+), Ag~+ could be complex with NH3, and co deposition of cobalt and silver bimetallic oxidation was formed at the anode. It is found that when the amount of NH3 is 150 mu L and the amount of deposition is ~1C, the catalytic performance of oxygen evolution is the best. The study shows that the active component is cobalt silver bimetal oxide and CO and Ag co catalysis.
【學(xué)位授予單位】：太原理工大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類(lèi)號(hào)】：O643.36;TQ116.2

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

1 王保偉;孫啟梅;;石墨烯在光催化水解制氫中的應(yīng)用[J];化工進(jìn)展;2012年10期

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本文編號(hào)：2024010