本文主要研究内容
作者刘一蒲（2019）在《基于电子结构优化的水裂解电催化材料的设计研究》一文中研究指出：电解水制氢技术是目前可持续、清洁制氢的关键技术。然而由于成本消耗过高,工业上利用该技术制备的氢气份额只占到氢气总产量的4%。电解水制氢技术中成本消耗来源之一来自于电解水两个半反应——产氢反应以及产氧反应的反应过电势所导致的能量消耗;而向电解水体系中引入催化材料可以改变相关反应能垒,进而有效降低反应过电势,提高能量转化效率。目前,催化电解水产氢及产氧反应活性最高的材料均为贵金属材料,分别为铂基催化剂及铱、钌基催化剂,而贵金属材料的极低丰度和极高价格作为另一成本消耗来源同样限制了电解水制氢技术发展。因此,发展电解水技术的一个关键方向是发展高活性的、廉价的非贵金属催化材料,使水裂解反应能量转化效率在最大化的同时真正地降低整体技术成本,进而得到广泛、可持续的发展。理想的电解水催化材料应该具备以下特点:（1）高催化活性,活性接近贵金属催化剂甚至超过贵金属催化剂;（2）高催化稳定性,需要具有稳定的催化结构防止材料失活,最好可以维持催化活性几年甚至几十年稳定不变;（3）材料组成廉价易得,以满足可持续发展策略;（4）材料合成方法简单易扩大,以满足大范围的工业需求。目前已知材料还无法达到以上标准,这需要在基础研究中大范围开发具有不同组成结构、催化特性的催化材料,并从中总结经验、发现规律,进而设计合成具有更高性能的催化材料,逐步实现最终目标。本论文以优化材料电子结构为导向,以理论计算分析为辅助工具,以调变材料晶相、引入异相结构及构建缺陷边位等策略为手段设计合成出一系列高性能的非贵金属电解水催化材料,并进一步通过对比研究分析对材料电子结构与催化性能间内在构效关系加以归纳与阐释。本论文主要研究内容如下:1.过渡金属碳化物由于其类铂的电子结构及类金属的高导电性,被认为是一类具有潜在优异性能的催化产氢材料;并且与大部分金属及合金材料只能在碱性条件下稳定运行不同,碳化物在较宽的pH条件下均能保持结构稳定,因此在催化反应领域具有更大优势。但是,已报道研究结果中单金属碳化物的催化产氢活性没有十分优异,因此本工作的出发点为向单金属碳化物体系中引入另一种金属,进而调制单金属碳化物电子结构,优化单金属碳化物催化产氢活性。基于以上思路,我们合成出了一种碳包覆碳化钨钴材料,这种材料在酸性、中性及碱性条件下均具有优异的催化活性及稳定性,特别在碱性条件下,该材料仅需73 mV即可以达到10 mA cm-2电流密度,活性远超单金属碳化物材料及其他组成材料。通过实验对比分析我们发现该材料的高催化产氢性能由双金属协同效应及碳包覆效应共同导致。该工作证实了双金属碳化物优化的电子结构对催化产氢反应的促进作用,为相关催化材料设计合成提供新思路。2.关于碳层对碳化物的影响,主流的观点一般认为合成碳化物时需要尽量避免碳层生成,因为碳是非催化活性相,附在碳化物上会减少碳化物活性位点数目,进而降低碳化物催化活性。然而根据对碳包覆碳化钨钴材料的研究工作,我们发现尽管碳化物材料被碳层完全包裹,但其催化性质完全不输表面洁净的碳化物材料,甚至具有更为优异的催化性能。基于以上矛盾点,我们简化合成体系合成出一系列碳包覆碳化钼材料,并以此为模型研究碳-碳化物异质结构对材料催化产氢性能的影响。通过实验我们发现材料催化活性与碳包覆材料中碳化物晶相结构、晶粒大小及氮元素含量有关,进一步的理论计算发现向碳化钼表面引入碳层可以有效调制整体材料的电子结构,使材料表面不会过强的吸附氢原子中间体,促进了催化产氢反应的发生;相应地底层碳化钼以及碳层中掺杂的氮元素共同调制了碳层中碳位点的电子结构,使该位点具有（35）GH*接近于0的高本征活性,进而解释了实验上材料的高催化产氢活性。该工作合成了具有高催化性能的碳包覆碳化钼材料,证实了碳层与碳化物之间的相互作用,同时指出了碳包覆策略是一种有效的提升碳化物催化活性以及催化稳定性的方法。3.导电硫化物材料是近期发展较为快速的一类催化材料。它们一般具有优异的导电性和结构稳定性,在催化产氢反应里具有极大优势。另外一些导电硫化物材料被报道同时具有催化产氧活性,即可利用同一种材料分别降低电解水两个半反应的能垒,进一步提高电解水整个反应的能量利用效率。基于以上设想,我们通过化学沉积法在泡沫铜基底上原位生长了准无定形的CoSx膜材料;通过结构表征我们发现反应过程中由于铜本身原子间较弱的结合力,基底上一部分的铜原子以亚纳米铜簇的形式扩散进CoSx膜材料中,形成了独特的亚纳米铜簇修饰的准无定形CoSx膜材料。通过实验分析我们发现准无定形CoSx膜材料与其相对应晶化结构相比具有更高的催化活性,同时材料中亚纳米铜簇的存在进一步提高了材料的导电性;相关理论计算证明铜簇结构与CoSx材料的结合可以使水分子更倾向以解离形式吸附在材料表面,加快了碱性条件下产氢反应中水的解离吸附过程。该种材料同时具有良好的产氧活性,基于此种特性我们利用该电极材料构建了双电极体系,该双电极体系在1.50 V电势下即可以达到10 mA cm-2电流密度,催化活性与Pt/C-IrO2体系相当,并具有更优异的稳定性,证实该材料是一类高性能双功能电解水催化材料。4.电解水产氧反应由于反应过程中涉及到多步电子/质子耦合过程,相比于产氢反应具有更迟缓的反应动力学,需要更大的过电势来克服反应能垒;并且由于产氧反应需要在较高的氧化条件下才能发生,很多物质在该条件下无法保持结构稳定,因此在催化产氧条件下维持材料的催化稳定性同样十分困难。LDH材料,特别是NiFe-LDH材料是一类活性优异的催化产氧材料,其结构可以在严苛的产氧条件下保持稳定,相关材料失活一般是催化材料与电极结合不牢固,催化过程中从电极表面剥落导致。基于以上研究基础,并且受自发生铁腐蚀反应的启发,我们通过控制铁基底腐蚀环境调控反应机理,室温条件下原位在铁基底材料上生长了阵列结构的NiFe-LDH纳米片材料;另外,通过调节腐蚀溶液中金属离子的浓度,我们可以进一步控制NiFe-LDH纳米片阵列材料的晶化程度。相关实验研究证实具有富晶界特征的NiFe-LDH纳米片阵列材料由于暴露了大量高活性不饱和位点,因此具有最高的催化产氧活性。我们进一步将富晶界NiFe-LDH材料生长在具有三维结构的泡沫铁材料上,该材料在碱性条件下仅需340 mV即可以达到1000 mA cm-2电流密度,并且可以在该电流密度下持续稳定工作5000小时以上。除了可以合成NiFe-LDH材料外,该种方法还可以进一步扩展合成CoFe,MnFe以及MgFe-LDH材料;并且由于该方法实现了在室温条件下无额外能量输入自发发生,方法易扩大且成本相对低廉,因此为工业化大批量生产该材料提供可能。
Abstract
dian jie shui zhi qing ji shu shi mu qian ke chi xu 、qing jie zhi qing de guan jian ji shu 。ran er you yu cheng ben xiao hao guo gao ,gong ye shang li yong gai ji shu zhi bei de qing qi fen e zhi zhan dao qing qi zong chan liang de 4%。dian jie shui zhi qing ji shu zhong cheng ben xiao hao lai yuan zhi yi lai zi yu dian jie shui liang ge ban fan ying ——chan qing fan ying yi ji chan yang fan ying de fan ying guo dian shi suo dao zhi de neng liang xiao hao ;er xiang dian jie shui ti ji zhong yin ru cui hua cai liao ke yi gai bian xiang guan fan ying neng lei ,jin er you xiao jiang di fan ying guo dian shi ,di gao neng liang zhuai hua xiao lv 。mu qian ,cui hua dian jie shui chan qing ji chan yang fan ying huo xing zui gao de cai liao jun wei gui jin shu cai liao ,fen bie wei bo ji cui hua ji ji yi 、liao ji cui hua ji ,er gui jin shu cai liao de ji di feng du he ji gao jia ge zuo wei ling yi cheng ben xiao hao lai yuan tong yang xian zhi le dian jie shui zhi qing ji shu fa zhan 。yin ci ,fa zhan dian jie shui ji shu de yi ge guan jian fang xiang shi fa zhan gao huo xing de 、lian jia de fei gui jin shu cui hua cai liao ,shi shui lie jie fan ying neng liang zhuai hua xiao lv zai zui da hua de tong shi zhen zheng de jiang di zheng ti ji shu cheng ben ,jin er de dao an fan 、ke chi xu de fa zhan 。li xiang de dian jie shui cui hua cai liao ying gai ju bei yi xia te dian :（1）gao cui hua huo xing ,huo xing jie jin gui jin shu cui hua ji shen zhi chao guo gui jin shu cui hua ji ;（2）gao cui hua wen ding xing ,xu yao ju you wen ding de cui hua jie gou fang zhi cai liao shi huo ,zui hao ke yi wei chi cui hua huo xing ji nian shen zhi ji shi nian wen ding bu bian ;（3）cai liao zu cheng lian jia yi de ,yi man zu ke chi xu fa zhan ce lve ;（4）cai liao ge cheng fang fa jian chan yi kuo da ,yi man zu da fan wei de gong ye xu qiu 。mu qian yi zhi cai liao hai mo fa da dao yi shang biao zhun ,zhe xu yao zai ji chu yan jiu zhong da fan wei kai fa ju you bu tong zu cheng jie gou 、cui hua te xing de cui hua cai liao ,bing cong zhong zong jie jing yan 、fa xian gui lv ,jin er she ji ge cheng ju you geng gao xing neng de cui hua cai liao ,zhu bu shi xian zui zhong mu biao 。ben lun wen yi you hua cai liao dian zi jie gou wei dao xiang ,yi li lun ji suan fen xi wei fu zhu gong ju ,yi diao bian cai liao jing xiang 、yin ru yi xiang jie gou ji gou jian que xian bian wei deng ce lve wei shou duan she ji ge cheng chu yi ji lie gao xing neng de fei gui jin shu dian jie shui cui hua cai liao ,bing jin yi bu tong guo dui bi yan jiu fen xi dui cai liao dian zi jie gou yu cui hua xing neng jian nei zai gou xiao guan ji jia yi gui na yu chan shi 。ben lun wen zhu yao yan jiu nei rong ru xia :1.guo du jin shu tan hua wu you yu ji lei bo de dian zi jie gou ji lei jin shu de gao dao dian xing ,bei ren wei shi yi lei ju you qian zai you yi xing neng de cui hua chan qing cai liao ;bing ju yu da bu fen jin shu ji ge jin cai liao zhi neng zai jian xing tiao jian xia wen ding yun hang bu tong ,tan hua wu zai jiao kuan de pHtiao jian xia jun neng bao chi jie gou wen ding ,yin ci zai cui hua fan ying ling yu ju you geng da you shi 。dan shi ,yi bao dao yan jiu jie guo zhong chan jin shu tan hua wu de cui hua chan qing huo xing mei you shi fen you yi ,yin ci ben gong zuo de chu fa dian wei xiang chan jin shu tan hua wu ti ji zhong yin ru ling yi chong jin shu ,jin er diao zhi chan jin shu tan hua wu dian zi jie gou ,you hua chan jin shu tan hua wu cui hua chan qing huo xing 。ji yu yi shang sai lu ,wo men ge cheng chu le yi chong tan bao fu tan hua wu gu cai liao ,zhe chong cai liao zai suan xing 、zhong xing ji jian xing tiao jian xia jun ju you you yi de cui hua huo xing ji wen ding xing ,te bie zai jian xing tiao jian xia ,gai cai liao jin xu 73 mVji ke yi da dao 10 mA cm-2dian liu mi du ,huo xing yuan chao chan jin shu tan hua wu cai liao ji ji ta zu cheng cai liao 。tong guo shi yan dui bi fen xi wo men fa xian gai cai liao de gao cui hua chan qing xing neng you shuang jin shu xie tong xiao ying ji tan bao fu xiao ying gong tong dao zhi 。gai gong zuo zheng shi le shuang jin shu tan hua wu you hua de dian zi jie gou dui cui hua chan qing fan ying de cu jin zuo yong ,wei xiang guan cui hua cai liao she ji ge cheng di gong xin sai lu 。2.guan yu tan ceng dui tan hua wu de ying xiang ,zhu liu de guan dian yi ban ren wei ge cheng tan hua wu shi xu yao jin liang bi mian tan ceng sheng cheng ,yin wei tan shi fei cui hua huo xing xiang ,fu zai tan hua wu shang hui jian shao tan hua wu huo xing wei dian shu mu ,jin er jiang di tan hua wu cui hua huo xing 。ran er gen ju dui tan bao fu tan hua wu gu cai liao de yan jiu gong zuo ,wo men fa xian jin guan tan hua wu cai liao bei tan ceng wan quan bao guo ,dan ji cui hua xing zhi wan quan bu shu biao mian jie jing de tan hua wu cai liao ,shen zhi ju you geng wei you yi de cui hua xing neng 。ji yu yi shang mao dun dian ,wo men jian hua ge cheng ti ji ge cheng chu yi ji lie tan bao fu tan hua mu cai liao ,bing yi ci wei mo xing yan jiu tan -tan hua wu yi zhi jie gou dui cai liao cui hua chan qing xing neng de ying xiang 。tong guo shi yan wo men fa xian cai liao cui hua huo xing yu tan bao fu cai liao zhong tan hua wu jing xiang jie gou 、jing li da xiao ji dan yuan su han liang you guan ,jin yi bu de li lun ji suan fa xian xiang tan hua mu biao mian yin ru tan ceng ke yi you xiao diao zhi zheng ti cai liao de dian zi jie gou ,shi cai liao biao mian bu hui guo jiang de xi fu qing yuan zi zhong jian ti ,cu jin le cui hua chan qing fan ying de fa sheng ;xiang ying de de ceng tan hua mu yi ji tan ceng zhong can za de dan yuan su gong tong diao zhi le tan ceng zhong tan wei dian de dian zi jie gou ,shi gai wei dian ju you （35）GH*jie jin yu 0de gao ben zheng huo xing ,jin er jie shi le shi yan shang cai liao de gao cui hua chan qing huo xing 。gai gong zuo ge cheng le ju you gao cui hua xing neng de tan bao fu tan hua mu cai liao ,zheng shi le tan ceng yu tan hua wu zhi jian de xiang hu zuo yong ,tong shi zhi chu le tan bao fu ce lve shi yi chong you xiao de di sheng tan hua wu cui hua huo xing yi ji cui hua wen ding xing de fang fa 。3.dao dian liu hua wu cai liao shi jin ji fa zhan jiao wei kuai su de yi lei cui hua cai liao 。ta men yi ban ju you you yi de dao dian xing he jie gou wen ding xing ,zai cui hua chan qing fan ying li ju you ji da you shi 。ling wai yi xie dao dian liu hua wu cai liao bei bao dao tong shi ju you cui hua chan yang huo xing ,ji ke li yong tong yi chong cai liao fen bie jiang di dian jie shui liang ge ban fan ying de neng lei ,jin yi bu di gao dian jie shui zheng ge fan ying de neng liang li yong xiao lv 。ji yu yi shang she xiang ,wo men tong guo hua xue chen ji fa zai pao mo tong ji de shang yuan wei sheng chang le zhun mo ding xing de CoSxmo cai liao ;tong guo jie gou biao zheng wo men fa xian fan ying guo cheng zhong you yu tong ben shen yuan zi jian jiao ruo de jie ge li ,ji de shang yi bu fen de tong yuan zi yi ya na mi tong cu de xing shi kuo san jin CoSxmo cai liao zhong ,xing cheng le du te de ya na mi tong cu xiu shi de zhun mo ding xing CoSxmo cai liao 。tong guo shi yan fen xi wo men fa xian zhun mo ding xing CoSxmo cai liao yu ji xiang dui ying jing hua jie gou xiang bi ju you geng gao de cui hua huo xing ,tong shi cai liao zhong ya na mi tong cu de cun zai jin yi bu di gao le cai liao de dao dian xing ;xiang guan li lun ji suan zheng ming tong cu jie gou yu CoSxcai liao de jie ge ke yi shi shui fen zi geng qing xiang yi jie li xing shi xi fu zai cai liao biao mian ,jia kuai le jian xing tiao jian xia chan qing fan ying zhong shui de jie li xi fu guo cheng 。gai chong cai liao tong shi ju you liang hao de chan yang huo xing ,ji yu ci chong te xing wo men li yong gai dian ji cai liao gou jian le shuang dian ji ti ji ,gai shuang dian ji ti ji zai 1.50 Vdian shi xia ji ke yi da dao 10 mA cm-2dian liu mi du ,cui hua huo xing yu Pt/C-IrO2ti ji xiang dang ,bing ju you geng you yi de wen ding xing ,zheng shi gai cai liao shi yi lei gao xing neng shuang gong neng dian jie shui cui hua cai liao 。4.dian jie shui chan yang fan ying you yu fan ying guo cheng zhong she ji dao duo bu dian zi /zhi zi ou ge guo cheng ,xiang bi yu chan qing fan ying ju you geng chi huan de fan ying dong li xue ,xu yao geng da de guo dian shi lai ke fu fan ying neng lei ;bing ju you yu chan yang fan ying xu yao zai jiao gao de yang hua tiao jian xia cai neng fa sheng ,hen duo wu zhi zai gai tiao jian xia mo fa bao chi jie gou wen ding ,yin ci zai cui hua chan yang tiao jian xia wei chi cai liao de cui hua wen ding xing tong yang shi fen kun nan 。LDHcai liao ,te bie shi NiFe-LDHcai liao shi yi lei huo xing you yi de cui hua chan yang cai liao ,ji jie gou ke yi zai yan ke de chan yang tiao jian xia bao chi wen ding ,xiang guan cai liao shi huo yi ban shi cui hua cai liao yu dian ji jie ge bu lao gu ,cui hua guo cheng zhong cong dian ji biao mian bao la dao zhi 。ji yu yi shang yan jiu ji chu ,bing ju shou zi fa sheng tie fu shi fan ying de qi fa ,wo men tong guo kong zhi tie ji de fu shi huan jing diao kong fan ying ji li ,shi wen tiao jian xia yuan wei zai tie ji de cai liao shang sheng chang le zhen lie jie gou de NiFe-LDHna mi pian cai liao ;ling wai ,tong guo diao jie fu shi rong ye zhong jin shu li zi de nong du ,wo men ke yi jin yi bu kong zhi NiFe-LDHna mi pian zhen lie cai liao de jing hua cheng du 。xiang guan shi yan yan jiu zheng shi ju you fu jing jie te zheng de NiFe-LDHna mi pian zhen lie cai liao you yu bao lou le da liang gao huo xing bu bao he wei dian ,yin ci ju you zui gao de cui hua chan yang huo xing 。wo men jin yi bu jiang fu jing jie NiFe-LDHcai liao sheng chang zai ju you san wei jie gou de pao mo tie cai liao shang ,gai cai liao zai jian xing tiao jian xia jin xu 340 mVji ke yi da dao 1000 mA cm-2dian liu mi du ,bing ju ke yi zai gai dian liu mi du xia chi xu wen ding gong zuo 5000xiao shi yi shang 。chu le ke yi ge cheng NiFe-LDHcai liao wai ,gai chong fang fa hai ke yi jin yi bu kuo zhan ge cheng CoFe,MnFeyi ji MgFe-LDHcai liao ;bing ju you yu gai fang fa shi xian le zai shi wen tiao jian xia mo e wai neng liang shu ru zi fa fa sheng ,fang fa yi kuo da ju cheng ben xiang dui di lian ,yin ci wei gong ye hua da pi liang sheng chan gai cai liao di gong ke neng 。
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论文作者分别是来自吉林大学的刘一蒲，发表于刊物吉林大学2019-06-25论文，是一篇关于电解水反应论文,电子结构论文,异相结构论文,碳化物论文,硫化物论文,双金属层状氢氧化物论文,吉林大学2019-06-25论文的文章。本文可供学术参考使用，各位学者可以免费参考阅读下载，文章观点不代表本站观点，资料来自吉林大学2019-06-25论文网站，若本站收录的文献无意侵犯了您的著作版权，请联系我们删除。
标签：电解水反应论文; 电子结构论文; 异相结构论文; 碳化物论文; 硫化物论文; 双金属层状氢氧化物论文; 吉林大学2019-06-25论文;