GOALI: Novel Impregnated Layer Combustion Synthesis for Catalysts Preparation: Hydrogen Production from Methanol

爱德华多·E.本工作的动机是需要找到一种可控的制备方法的高表面积的金属/氧化物催化剂，用于生产氢气的甲醇氧化重整（ORM）的小型燃料电池应用。该研究的目的是双重的：1）研究一种新的方法，用于催化剂制备的基础上的溶液燃烧合成，被称为嵌入层燃烧合成，或ILCS，和，2）开发的结构-活性相关性的催化剂制备的ILCS方法的ORM反应沿着光谱研究，以确定活性位点和链接那些与表面和材料性能。在PI组中进行的初步研究表明，通过共沉淀法制备的Pd/Cu/ZnO/ZrO 2催化剂对ORM反应具有活性和选择性。PI还将Cu金属表面积和氧化态确定为活性和选择性的决定因素。ILCS方法已经显示出产生高表面积氧化物以及负载在高表面积氧化物上的金属。ILCS方法涉及反应前沿在窄区域中短时间的受控传播，其沿着气体的逸出抑制粒度生长，导致形成高表面积（50-200 m2/g）、高纯度和结晶度的氧化物，其不需要额外的煅烧。通过使用ILCS，他们能够合成具有类似于共沉淀催化剂的高面积、活性和选择性的催化剂，这提供了概念证明。对ILCS方法的进一步研究有望产生更高的活性面积并提高活性和选择性。基于上述结果，他们假设：i）对ILCS的制备变量如何影响材料性质的基本理解将导致用于ORM反应的活性和选择性催化剂的设计，ii）建立ORM反应的结构-活性相关性可以导致更活性和选择性氧化催化剂的合理设计。详细的计划是计划研究如何在ILCS（溶液浓度，燃料组合物，基板浸渍，点火温度）中使用的制备变量影响散装材料和表面性质，如总的和活性表面积，结晶度，相组成，分散的促进剂，和氧化态在不同的环境下。将通过各种先进技术评价ILCS制备的各种催化剂的活性和选择性结果。将详细测量所选催化剂的动力学，以与材料性质和制备变量相关联。所选催化剂的EXAFS和IR光谱将用于确定催化剂的氧化态和反应条件下吸附物的类型（操作），并确定负责活性和选择性的关键表面变量。然后将来自动力学研究的速率常数与关键表面性质相关，并且这些又与ILCS制备变量相关。所得结果将提供新的知识的新型ILCS作为一种方法，为合理设计的氧化催化剂，以及从ORM制氢的决定因素。知识上的优点是，通过PI的综合专业知识，将在催化剂合成领域获得新的知识，应用于目前具有相当大的社会重要性并可能产生广泛的技术影响的问题。该综合计划将整合研究生水平的研究，并通过REU赠款在本科水平。计划通过拨出资金支持圣母院少数民族工程项目的努力，以帮助增加在工程领域代表性不足的群体的招聘，从而产生更广泛的教育影响。这些资金将支持一个外展计划，将未来的学生带到圣母院，并让他们参与与这一提议有关的实验。

Eduardo E. Wolf0730190This work is motivated by the need to find a controllable preparation method of high surface area metal/oxide catalysts for the production of hydrogen from the oxidative reforming of methanol (ORM) for small fuel cell applications. The objective of the research is twofold: 1) to study a novel method for catalyst preparation based on solution combustion synthesis, referred to as Impregnated Layer Combustion Synthesis, or ILCS, and, 2) develop structure-activity correlations of catalysts prepared by the ILCS method for the ORM reaction along with spectroscopic studies to identify active sites and links those with surface and material properties. Preliminary studies conducted in the PIs groups' show that Pd/Cu/ZnO/ZrO2 catalysts prepared by co-precipitation are active and selective for the ORM reaction. The PIs have also identified the Cu metal surface area and oxidation state as determining factors of activity and selectivity. The ILCS method has shown to yield high surface area oxides as well as metals supported onto high area oxides. The ILCS method involves the controlled propagation of a reaction front in a narrow area for a short time, which along with the evolution of gases, inhibits particle size growth leading to the formation of oxides of high surface area (50-200 m2/g), high purity and crystallinity, which do not require additional calcination. A proof of concept is provided that by using ILCS they were able to synthesize a catalyst that has high area and activity and selectivity similar to co-precipitated catalyst. Further studies of the ILCS method are expected to yield even higher active areas and increase activity and selectivity. On the basis of the above results they hypothesize that i) Fundamental understanding of how preparative variables of ILCS affect material properties will lead to the design of active and selective catalysts for the ORM reaction, ii) Establishing structure-activity correlations for ORM reactions could lead to the rational design of more active and selective oxidation catalysts. A detailed program is planned to study how the preparative variables used in ILCS (solution concentration, fuel composition, substrate impregnation, ignition temperature) affect the bulk material and surface properties such as total and active surface area, degree of crystallinity, phase composition, dispersion of promoters, and oxidation state under different environments. Activity and selectivity results for various catalysts prepared by ILCS will be evaluated by various advanced techniques. The kinetics of selected catalysts will be measured in detail for correlation with the material properties and preparative variables. EXAFS and IR spectroscopy of selected catalysts will be used to determine the catalysts' oxidation state and type of adsorbates under reaction conditions (operando) and to determine the key surface variable(s) responsible for activity and selectivity. The rate constants from the kinetics studies will be then correlated with the key surface properties and these in turn with the ILCS preparative variables. The results obtained will provide new knowledge of the novel ILCS as a method for the rational design of oxidation catalysts as well as the factors determining hydrogen production from the ORM. The intellectual merit is that through the combined expertise of the PIs, new knowledge will be gained in the field of catalysts synthesis applied to the problem that is currently of considerable societal importance and could have a broad technical impact. The comprehensive program proposed will integrate research at both the graduate level, and at undergraduate level via REU grants. A broader educational impact is planned by setting aside funds for supporting the effort of the minority engineering program at Notre Dame to help increase recruiting of underrepresented groups in engineering. The funds will support an outreach program to bring prospective students to Notre Dame and have them participate on experiments related to this proposal.