Hierarchical 2D/3D nanosheet materials for the production of hydrogen from methane without the formation of CO2 and for water purification.

人类向大气中释放的二氧化碳是可测量的，不可否认。二氧化碳是化石燃料完全燃烧所带来的社会工业化的废物。除水外，它是由完全燃烧产生的最低能（可用功）的化合物。它代表燃烧产生的价值最低的废物。它很难从氮气中分离出来，也很难压缩和运输到处理场并最终注入地下。越来越多的问题是，在一万年的时间里，它是否会从水库中泄漏出来。我们可以通过这些燃料生产氢和纯碳来做得更好。氢可以燃烧作为能量，而碳可以作为固体储存起来。这项提议的目标是开发新的催化剂和工艺，可以利用甲烷中含有的部分能量产生固体碳。这将通过申请人实验室生产的一类新的2D/3D纳米材料来完成。******在过去的十年中，许多分层多孔材料已经被开发出来。由于其更大的表面积和更易于接近的催化活性位点，它们已经证明了比传统材料更好的性能。这些进展大多是基于一类被称为层状双氢氧化物（LDH）的阴离子粘土。采用共沉淀法、离子交换法、煅烧-再水合法、水热法和电化学法制备了低密度氢氧化钠。然而，用这些方法制备的ldh通常是石状或板状的，并且表面积有限。为了潜在的应用，它们需要改进。我们已经成功地合成了具有200 nm宽的狭缝形状的孔隙的2D/3D纳米板材料。这些狭缝状的孔隙仿造了人类肾脏中的孔隙。这种形状对蛋白质和胶体的污染具有相当大的抵抗力。******最近，我们加强了在实验室中开发的2D/3D纳米血小板，将它们放置在填充床中，并研究了通过这些床的染料的分散。研究发现，纳米颗粒在床上的分散度比文献中报道的所有包装材料低10倍。这些最新的结果证实了狭缝孔几何形状的优势和这些新型填料的等孔性质。******这项工作的目标是从纳米血小板中产生自组装结构，并将其增强用于填充床和膜。这些结构将具有裂缝状的孔隙几何形状。它们将在甲烷催化分解生成氢和碳的过程中进行测试。它们还将作为陶瓷和金属支架上的精细过滤器沉积，以处理含有胶体和细颗粒的废水，以减少膜污染。这项工作的结果将导致一种新的碳封存形式，并产生高性能的膜

The anthropogenic release of carbon dioxide to the atmosphere is measurable and cannot be denied. CO2 is a waste product of society's industrialization brought about by the complete combustion of fossil fuels. After water, it is the compound that contains the lowest exergy (available work) from complete combustion. It represents the waste having the lowest value from combustion. It is difficult to separate from nitrogen, difficult to compress and transport to a disposal site and finally inject underground. There are increasing questions as to whether it will leak from reservoirs over a period of 10,000 years. We can do better by producing hydrogen and pure carbon from these fuels. The hydrogen could be burnt for energy and the carbon stored as a solid. The objective of this proposal is to develop new catalysts and processes that can harness part of the energy contained in methane and produce solid carbon. This will be done with a new class of 2D/3D nanomaterials to be produced in the applicant's lab. ******Many hierarchically porous materials have been developed over the past ten years. They have demonstrated improved performance over conventional materials due to their greater surface area and improved accessibility to catalytically active sites. Most of these advancements have been based on a class of anionic clays known as layered double hydroxides (LDH). LDHs have been prepared by several methods such as co-precipitation, ion exchange, calcination-rehydration, hydrothermal and electrochemical. However, LDHs prepared by these methods are usually stone-like or plate-like and have limited surface areas. They need to be improved for potential applications. We have successfully synthesized 2D/3D nanoplatelet materials that have pores in the shape of slits of 200 nm width. These slit-like pores biomimic the pores found in the human kidney. This shape offers considerable resistance to fouling by proteins and colloids.******Most recently we have reinforced the 2D/3D nanoplatelets developed in our laboratories, placed them in packed beds and studied the dispersion of dyes passing through these beds. The nanoparticles were found to pack in beds that have a 10-fold lower dispersion than all packing materials reported in the literature. These latest results confirm the advantages of the slit pore geometries and the isoporous nature of these new packing materials. ******The objective of this work will be to produce self-assembled structures from nanoplatelets and reinforce them for use in packed beds and membranes. These structures will have slit-like pore geometries. They will be tested in the catalytic decomposition of methane to form hydrogen and carbon. They will also be deposited as fine filters on ceramic and metal supports to treat wastewaters containing colloids and fine particulates in order to reduce membrane fouling. The results of this work will lead to a new form of carbon sequestering and produce high-performance membranes.**