Yu Qiu

Bio: Yu Qiu is an academic researcher from Southeast University. The author has contributed to research in topics: Chemical looping combustion & Oxygen. The author has an hindex of 10, co-authored 29 publications receiving 354 citations.

Enhanced hydrogen production performance through controllable redox exsolution within CoFeAlOx spinel oxygen carrier materials

Abstract: The high reaction temperature required for chemical looping in water splitting presents challenges in terms of producing stable oxygen carrier materials (OCMs). The currently available materials are generally prepared by a deposition method through which iron oxides and refractory supports are spatially separated, thus having low activity and stability. Here, we report CoFeAlOx as an OCM, in which the active phase of the CoFe alloy and the parent spinel support are homogeneously mixed into a solid solution. Using a variety of characterization techniques, we studied the exsolution and dissolution effects of the CoFe alloy on the spinel support in a chemical looping redox cycle and found that the exsolution process can be tailored by the reduction level, which determines the interface structure. When reduced by CO, the exsolved particles were similar to the deposited analogues, showing obvious sintering. However, for the sample reduced by CO and CO2, the exsolved CoFe alloy can be embedded into the support, with it re-emerging fresh and confined at each reduction period. After 20 cycles, it showed a high hydrogen production rate and outstanding stability, demonstrating that the controllable exsolution could significantly improve the high temperature redox performance. Based on these results, this study also provides a new dimension for designing improved redox materials for chemical looping, calcium looping, or solar-driven thermochemical applications.

Chemical looping beyond combustion – a perspective

Abstract: As a promising approach for carbon dioxide capture, chemical looping combustion has been extensively investigated for more than two decades. However, the chemical looping strategy can be and has been extended well beyond carbon capture. In fact, significant impacts on emission reduction, energy conservation, and value-creation can be anticipated from chemical looping beyond combustion (CLBC). This article aims to demonstrate the versatility and transformational benefits of CLBC. Specifically, we focus on the use of oxygen carriers or redox catalysts for chemical production – a $4 trillion industry that consumes 40.9 quadrillion BTU of energy. Compared to state-of-the-art chemical production technologies, we illustrate that chemical looping offers significant opportunities for process intensification and exergy loss minimization. In many cases, an order of magnitude reduction in energy consumption and CO2 emission can be realized without the needs for carbon dioxide capture. In addition to providing various CLBC examples, this article elaborates on generalized design principles for CLBC, potential benefits and pitfalls, as well as redox catalyst selection, design, optimization, and redox reaction mechanism.

Chemical Looping Conversion of Gaseous and Liquid Fuels for Chemical Production: A Review

Abstract: Chemical looping technology enables achievement of the simultaneous feedstock conversion and product separation without additional processes via circulating solid intermediates (so-called oxygen/ni...