等離子體在綠色制備催化劑方面的應(yīng)用:現(xiàn)狀及展望（英文）
發(fā)布時(shí)間：2018-11-08 13:13
【摘要】：催化在現(xiàn)代化工生產(chǎn)中正發(fā)揮非常重要的作用.在未來(lái)催化甚至?xí)缪莞匾慕巧?然而,現(xiàn)有的催化劑制備方法會(huì)對(duì)空氣、水和土地造成污染.這些污染主要來(lái)源于催化劑制備過(guò)程中會(huì)用到的各種有害化學(xué)品.而且,現(xiàn)有催化劑制備過(guò)程耗時(shí)長(zhǎng)、耗能高、用水量大.這些都不符合綠色化學(xué)原則.因此,開(kāi)展催化劑綠色制備研究十分必要.這一研究的長(zhǎng)遠(yuǎn)目標(biāo)是避免或者消除催化劑制備過(guò)程每一環(huán)節(jié)產(chǎn)生的污染,降低每一環(huán)節(jié)的能耗和物耗,縮短制備時(shí)間,減少勞動(dòng)強(qiáng)度.顯然,這并不是一個(gè)容易達(dá)成的目標(biāo).因此,朝著上述長(zhǎng)遠(yuǎn)目標(biāo)的任何進(jìn)展,無(wú)論是小進(jìn)展還是大進(jìn)展,都將有助于最終實(shí)現(xiàn)催化劑的綠色制備.我們總結(jié)了氣體放電冷等離子體在催化劑綠色制備方面的最新進(jìn)展,特別強(qiáng)調(diào)了非氫冷等離子體在催化劑制備中的應(yīng)用.冷等離子體是一種能在室溫附近操作的非平衡等離子體,是對(duì)氣體施加一定電壓(數(shù)百至上萬(wàn)伏特;具體電壓值取決于氣體壓力)形成的.冷等離子體制備方法可以在少用或者不用有害化學(xué)品的基礎(chǔ)上,有效減小催化劑粒徑、增加催化劑分散度、提高催化劑和載體的相互作用等.這些改進(jìn)同時(shí)能進(jìn)一步提高催化劑的活性和穩(wěn)定性.相對(duì)于常規(guī)熱化學(xué)制備催化劑,冷等離子體制備的顯著區(qū)別在于:冷等離子體在室溫或者略高于室溫條件下操作,可以有效避免熱化學(xué)方法存在的缺點(diǎn).冷等離子體方法利用其富含的高能物質(zhì)(如電子)快速促進(jìn)催化劑前驅(qū)體分解,從而實(shí)現(xiàn)催化劑快速成核.由于低溫操作,其晶體生長(zhǎng)速度受到限制,催化劑分散性得以提高.研究表明,以非氫等離子體作為電子源的室溫電子還原能夠有效還原貴金屬離子.這個(gè)過(guò)程中既不需要有害化學(xué)還原劑也不需要?dú)溥�原.這為以熱敏材料和化學(xué)不穩(wěn)定物質(zhì)作為基底的負(fù)載型催化劑制備創(chuàng)造了條件.這些熱敏材料包括金屬有機(jī)骨架材料(MOF)、共價(jià)有機(jī)骨架材料(COF)、高比表面積的碳、多肽、DNA和蛋白質(zhì)等等.這個(gè)室溫電子還原還被用于制備能在水面或其它溶液表面上漂浮的催化劑,對(duì)發(fā)展新型催化劑有很大幫助.此外,使用冷等離子體還可以進(jìn)行低溫模板脫除,以避免高溫分解可能出現(xiàn)的燒結(jié)問(wèn)題,在保證催化劑高比表面積的同時(shí)獲得只有在高溫分解才能得到的結(jié)構(gòu)特征.研究表明,可以使用冷等離子體誘發(fā)微燃燒以除去炭模板,可以有效減少炭模板法制備氧化物結(jié)構(gòu)材料所需要的化學(xué)品.冷等離子體方法在催化劑制備中的應(yīng)用剛剛開(kāi)始,尚有大量研究還有待于開(kāi)展(如多金屬氧化物制備等),存在大量研發(fā)機(jī)會(huì).可以預(yù)期,冷等離子體在催化劑綠色制備與應(yīng)用中將發(fā)揮更重要的作用.
[Abstract]:Catalysis is playing a very important role in modern chemical production. Catalysis will play an even more important role in the future. However, existing methods of preparing catalysts can pollute air, water and land. These pollution mainly come from various harmful chemicals used in the preparation of catalysts. Moreover, the existing catalyst preparation process takes a long time, high energy consumption and high water consumption. None of this is in line with green chemistry principles. Therefore, it is necessary to study the green preparation of catalysts. The long-term goal of this study is to avoid or eliminate the pollution in every link of catalyst preparation, to reduce energy consumption and material consumption, to shorten preparation time and to reduce labor intensity. Clearly, this is not an easy goal to achieve. Therefore, any progress towards these long-term goals, whether small or significant, will contribute to the eventual green preparation of catalysts. The recent progress in the green preparation of catalysts by gas discharge cold plasma is summarized, especially the application of non-hydrogen cold plasma in the preparation of catalysts is emphasized. Cold plasma is a kind of non-equilibrium plasma which can operate near room temperature. It is formed by applying a certain voltage (hundreds to tens of thousands volts; the specific voltage depends on the pressure of the gas). The cold plasma preparation method can effectively reduce the particle size of the catalyst, increase the dispersion of the catalyst and improve the interaction between the catalyst and the support on the basis of less or no harmful chemicals. These improvements can further improve the activity and stability of the catalyst. Compared with conventional thermochemical preparation catalysts, the difference of cold plasma preparation is that cold plasma operating at room temperature or slightly higher than room temperature can effectively avoid the disadvantages of thermochemical method. The cold plasma method can rapidly promote the decomposition of catalyst precursors by using its rich high energy materials (such as electrons) so as to realize the rapid nucleation of catalysts. Due to the low temperature operation, the crystal growth rate is limited and the dispersion of the catalyst is improved. The results show that the room temperature electron reduction with non-hydrogen plasma as the electron source can effectively reduce noble metal ions. This process requires neither harmful chemical reductants nor hydrogen reduction. This creates conditions for the preparation of supported catalysts based on thermosensitive materials and chemical unstable substances. These thermosensitive materials include metal-organic skeleton material (MOF), covalent organic skeleton material (COF), with high specific surface area carbon polypeptide DNA and protein. This room temperature electron reduction is also used to prepare catalysts that can float on the surface of water or other solutions, which is of great help to the development of new catalysts. In addition, the cold plasma can be used to remove the template at low temperature to avoid the possible sintering problem of the decomposition at high temperature, and to obtain the structural characteristics which can only be obtained by decomposition at high temperature while ensuring the high specific surface area of the catalyst. The results show that the cold plasma-induced micro-combustion can be used to remove the carbon template, and the chemicals needed for the preparation of oxide structure materials can be effectively reduced by the carbon template method. The application of the cold plasma method in the preparation of catalysts is just beginning, there are still a lot of research needs to be carried out (such as the preparation of polymetallic oxides), there are a lot of research and development opportunities. It is expected that cold plasma will play a more important role in the green preparation and application of catalysts.
【作者單位】： 天津大學(xué)化工學(xué)院天津化學(xué)化工協(xié)同創(chuàng)新中心;
【基金】：supported by the National Natural Science Foundation of China(20990223 and 21476157)~~
【分類(lèi)號(hào)】：O643.36
，
本文編號(hào)：2318602
[Abstract]:Catalysis is playing a very important role in modern chemical production. Catalysis will play an even more important role in the future. However, existing methods of preparing catalysts can pollute air, water and land. These pollution mainly come from various harmful chemicals used in the preparation of catalysts. Moreover, the existing catalyst preparation process takes a long time, high energy consumption and high water consumption. None of this is in line with green chemistry principles. Therefore, it is necessary to study the green preparation of catalysts. The long-term goal of this study is to avoid or eliminate the pollution in every link of catalyst preparation, to reduce energy consumption and material consumption, to shorten preparation time and to reduce labor intensity. Clearly, this is not an easy goal to achieve. Therefore, any progress towards these long-term goals, whether small or significant, will contribute to the eventual green preparation of catalysts. The recent progress in the green preparation of catalysts by gas discharge cold plasma is summarized, especially the application of non-hydrogen cold plasma in the preparation of catalysts is emphasized. Cold plasma is a kind of non-equilibrium plasma which can operate near room temperature. It is formed by applying a certain voltage (hundreds to tens of thousands volts; the specific voltage depends on the pressure of the gas). The cold plasma preparation method can effectively reduce the particle size of the catalyst, increase the dispersion of the catalyst and improve the interaction between the catalyst and the support on the basis of less or no harmful chemicals. These improvements can further improve the activity and stability of the catalyst. Compared with conventional thermochemical preparation catalysts, the difference of cold plasma preparation is that cold plasma operating at room temperature or slightly higher than room temperature can effectively avoid the disadvantages of thermochemical method. The cold plasma method can rapidly promote the decomposition of catalyst precursors by using its rich high energy materials (such as electrons) so as to realize the rapid nucleation of catalysts. Due to the low temperature operation, the crystal growth rate is limited and the dispersion of the catalyst is improved. The results show that the room temperature electron reduction with non-hydrogen plasma as the electron source can effectively reduce noble metal ions. This process requires neither harmful chemical reductants nor hydrogen reduction. This creates conditions for the preparation of supported catalysts based on thermosensitive materials and chemical unstable substances. These thermosensitive materials include metal-organic skeleton material (MOF), covalent organic skeleton material (COF), with high specific surface area carbon polypeptide DNA and protein. This room temperature electron reduction is also used to prepare catalysts that can float on the surface of water or other solutions, which is of great help to the development of new catalysts. In addition, the cold plasma can be used to remove the template at low temperature to avoid the possible sintering problem of the decomposition at high temperature, and to obtain the structural characteristics which can only be obtained by decomposition at high temperature while ensuring the high specific surface area of the catalyst. The results show that the cold plasma-induced micro-combustion can be used to remove the carbon template, and the chemicals needed for the preparation of oxide structure materials can be effectively reduced by the carbon template method. The application of the cold plasma method in the preparation of catalysts is just beginning, there are still a lot of research needs to be carried out (such as the preparation of polymetallic oxides), there are a lot of research and development opportunities. It is expected that cold plasma will play a more important role in the green preparation and application of catalysts.
【作者單位】： 天津大學(xué)化工學(xué)院天津化學(xué)化工協(xié)同創(chuàng)新中心;
【基金】：supported by the National Natural Science Foundation of China(20990223 and 21476157)~~
【分類(lèi)號(hào)】：O643.36
，
本文編號(hào)：2318602
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