About

Fanxing Li is the Thomas M. Clausi Distinguished Professor and University Faculty Scholar at North Carolina State University. He holds a B.S. and M.S. in Chemical Engineering from Tsinghua University, earned in 2001 and 2004 respectively, and completed his Ph.D. in Chemical Engineering at The Ohio State University in 2009. As the Principal Investigator of the Li Research Group, Professor Li leads a team of researchers focused on advancing chemical engineering through innovative research. His leadership is reflected in the diverse expertise of his group members, including postdoctoral researchers and doctoral students working on various aspects of catalysis, energy conversion, and sustainable chemical processes. Professor Li's work contributes significantly to the development of catalytic materials and reactor systems aimed at improving energy efficiency and environmental sustainability in chemical production.

Research topics

• Organic chemistry
• Chemistry
• Chemical engineering
• Inorganic chemistry
• Computer Science
• Materials science
• Nanotechnology
• Biochemistry
• Composite material
• Photochemistry
• Engineering
• Mathematics
• Environmental science
• Biochemical engineering
• Computational chemistry

Selected publications

• Chemical-Looping Reforming of Methane with Tunable CO ₂ Utilization over Ruddlesden–Popper and Perovskite Carriers

  Industrial & Engineering Chemistry Research · 2026-01-04

  articleSenior authorCorresponding

  This work demonstrates that the Ruddlesden–Popper (RP) structured (Sr0.5La0.5)2Fe0.625Cu0.375O4 functions as a redox catalyst and/or a CO2 sorbent to enable three syngas-generation pathways from methane and CO2 or CO2-containing flue gas with tunable syngas composition: (i) sorption-looping dry reforming of methane (SLDRM) using O2-free CO2; (ii) SLDRM coupled with redox reactions under extended cycle duration; and (iii) integrated SLDRM/partial oxidation (POx) using O2 and CO2-containing flue gas. In the O2-containing mode, flue-gas CO2 is captured and utilized in SLDRM while residual O2 drives methane POx, partially offsetting the SLDRM endotherm. Phase-dependent behavior under reaction conditions explains this flexibility: (Sr0.5La0.5)2Fe0.625Cu0.375O4 converts to SrLaFeO4 and Cu/SrO components, where Cu/SrO captures CO2 and SrLaFeO4 is redox-active. In contrast, the perovskite Sr0.5La0.5Fe0.625Cu0.375O3, without excess Sr, acts primarily as an oxygen carrier, indicating that the as-synthesized structure/composition governs the reaction pathway, syngas ratio, and suitable process configuration.

  PublisherDOI

• Zr-promoted Ni nanoparticles in mesoporous silica spheres (NiZr/mSiO2) for catalytic decomposition of methane

  Chemical Engineering Journal · 2025-02-11 · 12 citations

  articleOpen accessSenior authorCorresponding

  • Mesoporous SiO 2 spheres ( m SiO 2 ) are synthesized and loaded with small and uniform Ni NPs and promoters (Cu, Ce, Zr). • A high-performance and regenerable m SiO 2 -NiZr catalyst at T = 600 °C and WHSV = 24 L·g cat –1 ·h −1 . • Zr promotes Ni reducibility, higher activity, and less tip-growth for CNTs, but expedites the deactivation rate. • CNTs were formed with uniform diameters and high quality. Catalytic decomposition of methane (CDM) is a promising method for producing carbon nanotubes (CNTs) and H 2 at-scale, with net-zero CO 2 emission. Herein, a highly active CDM catalyst is presented comprised of inert mesoporous silica spheres ( m SiO 2 ) as a support loaded with Ni nanoparticles (NPs) and dopants, resulting in high CH 4 conversion and potential inhibition of tip-growth CNTs. Specifically, uniformly dispersed Ni NPs onto m SiO 2 promoted by scant Zr deposition (rendering NiZr/ m SiO 2 ) exhibited decent reducibility and an excellent H 2 production rate (4.52 mol H2 ·g Ni –1 ·h −1 at T = 600 °C and GHSV = 24 L·g cat –1 ·h −1 ). As the best-performing catalyst, 10Ni0.2Zr/ m SiO 2 exhibited satisfactory long-term stability with a low deactivation rate and cyclability performance with marginal activity loss over 10 cycles. Besides, the CNTs growth mode from tip-growth to base-growth could be switched by altering the synthetic chemistry of inert m SiO 2 but at the expense of catalytic activity.

  PublisherDOI

• Powerful Foldover Designs

  Quality and Reliability Engineering International · 2025-10-21

  articleSenior author

  ABSTRACT The foldover technique for screening designs is well‐known to guarantee zero aliasing of the main effect estimators with respect to two‐factor interactions and quadratic effects. It is a key feature of many popular response surface designs, including central composite designs, definitive screening designs, and most orthogonal, minimally aliased response surface designs. In this paper, we show that the foldover technique is even more powerful, because it produces degrees of freedom for a variance estimator that is independent of model selection. These degrees of freedom are characterized as either pure error or fake factor degrees of freedom. A fast design construction algorithm is presented that minimizes the expected confidence interval criterion to maximize the power of screening main effects. An augmented design and analysis method is also presented to avoid having too many degrees of freedom for estimating variance and to improve model selection performance for second‐order models. Simulation studies show that our new designs are at least as good as traditional designs when effect sparsity and hierarchy hold, but do significantly better when these effect principles do not hold. A real data example is given for a 20‐run experiment where optimization of ethylene concentration is performed by manipulating eight process parameters.

  PublisherDOI

• CO2-Utilization Facilitated by Solid Reaction Mediums—A Review

  Korean Journal of Chemical Engineering · 2025-03-23 · 2 citations

  articleOpen accessSenior author

  Abstract This short review examines solid reaction mediums—specifically oxygen, CO 2 , and carbon carriers—within the framework of Chemical Looping (CL) to illuminate various CO 2 utilization pathways. The thermodynamic consideration for carrier selection is first discussed. This is followed by a summary of the key carrier types investigated to date, with an emphasis on elucidating the roles of compositional, structural, and surface properties of the various carriers toward their reactive performances. Besides assessing the performances of various oxygen carriers, their long-term performance, potential deactivation mechanism in the presence of CO 2, and strategies for their reactivation are also discussed in the context of chemical looping dry reforming of methane (CLDRM). While relatively underexplored, the current status of development, advantages, and potential limitations of CO 2 carriers in sorbent looping dry reforming of methane (SLDRM) and carbon carriers in chemical looping methane cracking (CLMC) are also reviewed and discussed. Emerging topics such as combined carriers are also covered along with a perspective for future research directions. Overall, this review aims to offer insights into the sustainable use of CO 2 through chemical looping, emphasizing the potential of solid reaction mediums across different carriers and the challenges associated with these solid reaction mediums.

  PublisherOA PDFDOI

• ABPT: Amended Backpropagation through Time with Partially Differentiable Rewards

  ArXiv.org · 2025-01-24

  preprintOpen access1st authorCorresponding

  Quadrotor control policies can be trained with high performance using the exact gradients of the rewards to directly optimize policy parameters via backpropagation-through-time (BPTT). However, designing a fully differentiable reward architecture is often challenging. Partially differentiable rewards will result in biased gradient propagation that degrades training performance. To overcome this limitation, we propose Amended Backpropagation-through-Time (ABPT), a novel approach that mitigates gradient bias while preserving the training efficiency of BPTT. ABPT combines 0-step and N-step returns, effectively reducing the bias by leveraging value gradients from the learned Q-value function. Additionally, it adopts entropy regularization and state initialization mechanisms to encourage exploration during training. We evaluate ABPT on four representative quadrotor flight tasks \li{in both real world and simulation}. Experimental results demonstrate that ABPT converges significantly faster and achieves higher ultimate rewards than existing learning algorithms, particularly in tasks involving partially differentiable rewards. The code will be released at http://github.com/Fanxing-LI/ABPT.

  PublisherOA PDFDOI

• Powerful Foldover Designs

  ArXiv.org · 2025-07-19

  articleOpen accessSenior author

  The foldover technique for screening designs is well known to guarantee zero aliasing of the main effect estimators with respect to two factor interactions and quadratic effects. It is a key feature of many popular response surface designs, including central composite designs, definitive screening designs, and most orthogonal, minimally-aliased response surface designs. In this paper, we show the foldover technique is even more powerful, because it produces degrees of freedom for a variance estimator that is independent of model selection. These degrees of freedom are characterized as either pure error or fake factor degrees of freedom. A fast design construction algorithm is presented that minimizes the expected confidence interval criterion to maximize the power of screening main effects. An augmented design and analysis method is also presented to avoid having too many degrees of freedom for estimating variance and to improve model selection performance for second order models. Simulation studies show our new designs are at least as good as traditional designs when effect sparsity and hierarchy hold, but do significantly better when these effect principles do not hold. A real data example is given for a 20-run experiment where optimization of ethylene concentration is performed by manipulating eight process parameters.

  PublisherOA PDF

• Strontium Iron Hexaaluminates for CO _<i>x</i> -Free Hydrogen and Carbon Nanotubes via Catalytic Decomposition of Methane

  ACS Catalysis · 2025-11-29 · 2 citations

  articleSenior authorCorresponding

  In this study, a set of iron-substituted strontium hexaaluminate materials (SrFexAl12–xO19) were synthesized and evaluated for catalytic methane decomposition (CDM) using a concentrated methane feed (PCH4 = 0.9 atm). Despite their lower surface areas, it is showcased that the SrFexAl12–xO19 materials can be quite active for CDM, reaching overall carbon yields up to 8.08 gC·gcat–1 or 15.68 gC·gFe–1 at GHSV = 5 L·g–1·h–1. In situ XRD under a reducing environment indicates that catalytic activity for high iron-containing samples (x ≥ 6) originates from the collapse of the parent SrFexAl12–xO19 structure to α-Fe supported on residual SrAl2O4 and FeAl2O4. Further in situ XRD studies on bulk Fe3C under the presence of CH4 show that iron carbide is metastable and will transform to BCC α-Fe in the range between 600 and 800 °C and subsequently to FCC γ-Fe and Fe3C ≥900 °C. Analogous in situ XRD experiments on SrFe9Al3O19 under CH4 show a clear sequential phase transformation of α-Fe → γ-Fe → Fe3C and the evolution of a small amount of graphite after testing, which suggests that Fe3C is catalytically active for CDM. Density functional theory (DFT) calculations further probed the energetics of surface carbon diffusion on Fe3C and methane dehydrogenation on low-index facets of BCC α-Fe, FCC γ-Fe, and Fe3C, respectively. These results, based on in situ measurements coupled with detailed ab initio calculations, give nuanced perspectives on the active phases for iron-based CDM catalysts and CNT growth.

  PublisherDOI

• Metal Organic Framework Impregnated Nanofibrous Aerogels: A 3D Structured Matrix for CO₂ Capture

  ACS Applied Materials & Interfaces · 2025-04-17 · 5 citations

  article

  This study explores the synthesis and functionality of mesoporous UiO-66-NH2 metal–organic framework (MOF) impregnated cellulose diacetate (CDA)-silica hybrid nanofibrous aerogels (NFAs) for selective CO2 capture. Mesoporous MOFs generally outperform microporous MOFs for CO2 capture, while NFAs provide a lightweight, highly porous material platform consisting of a three-dimensional (3D) network of interlinked nanofibers, offering both mechanical strength and a larger surface area. We exploit the attributes of these candidate materials by producing CDA-silica@UiO-66-NH2 NFA through a simple freeze-drying process involving a mixture of CDA-silica nanofiber dispersions and mesoporous UiO-66-NH2 nanoparticles in tert-butanol, avoiding cumbersome pre- or postprocessing typical in aerogel synthesis. The aerogels exhibit a hierarchical porous structure, allow for MOF loadings of up to 80 wt %, and demonstrate remarkable CO2 adsorption performance, with a direct correlation between MOF content and adsorption efficiency. Notably, an NFA containing 80 wt % MOF achieves a CO2 uptake of 2.5 mmol/g at 35 °C and atmospheric pressure. The CDA-silica@UiO-66-NH2 NFA also exhibits a strong preference for CO2 adsorption compared to N2 across all pressure levels when exposed to a gas mixture of CO2 and N2 in an 85:15 ratio. The CO2/N2 selectivity (Sads) usually calculated by using the ideal adsorption solution theory (IAST) reveals a value of 18.2 at 298 °K for this system. The NFA also displays strong mechanical resiliency including compressibility and fatigue resistance, and MOF integration without detachment during multiple compression cycles. Unlike traditional CO2 capture materials, our CDA-silica@UiO-66-NH2 NFA with a combination of high CO2 selectivity, structural integrity, and ease of fabrication thus offers a potentially scalable solution that addresses both performance and durability in real-world applications.

  PublisherDOI

• GRU-PatchTST-Based Feedforward Compensation for High-Precision Motion Control

  2025-09-26

  article

  To provide the wafer stage with a motion control method that ensures both excellent tracking accuracy and strong generalization capability, a neural network-based feedforward control strategy is proposed that employs a gated recurrent unit-patch long term transformer network (GRU-PatchTST) to accurately predict feedforward compensation signals. First, a GRU-PatchTST network is constructed, which utilizes data collected from the wafer stage to precisely predict the feedforward compensation term corresponding to the reference trajectory. Essentially, the GRU-PatchTST network can be regarded as a data-driven model that accurately characterizes the inverse dynamics of the system, thereby serving as an effective feedforward controller. Comparative experiments demonstrate the effectiveness of the prediction capability of the GRU-PatchTST and verify the superior tracking performance of the proposed feedforward control method. The proposed approach not only achieves control accuracy comparable to iterative learning control but also eliminates the need for a cumbersome iterative process. The optimal feedforward compensation term can be obtained from a single rediction, which highlights the practical applicability of the method.

  PublisherDOI

• Reversible Phase Transitions Enable Cyclic Isothermal CO₂ Capture in Redox‐Activated Perovskite‐Structured Sorbents

  Advanced Functional Materials · 2025-07-25

  articleOpen accessSenior authorCorresponding

  Abstract Sorption‐enhanced steam reforming and gasification using CO 2 sorbents enable the production of H 2 ‐rich syngas from carbonaceous feedstocks but are limited by significant temperature swings and sintering‐induced activity loss. Perovskite‐structured oxides are presented herein as sintering‐resistant, redox‐activated isothermal CO 2 sorbents capable of overcoming these challenges by releasing lattice oxygen to partially oxidize the carbonaceous feedstock while capturing CO 2 , shifting equilibrium toward H 2 production. Building on this, the structural and thermodynamic impact of Fe doping on the CO 2 sorption properties of SrMn 1‐ x Fe x O 3‐ δ is investigated for sorption‐enhanced reforming. Experimental results demonstrate that these sorbents enable isothermal production of high‐quality, H 2 ‐enriched syngas from carbonaceous feedstocks. Laboratory and synchrotron‐based powder X‐ray diffraction analyses, coupled with density functional theory calculations, reveal the structural dynamics and energy landscape of the SrMn 1‐ x Fe x O 3‐ δ perovskite system under reaction conditions, elucidating the solid‐state reaction pathway and the effect of Fe doping on the extent of carbonation.

  PublisherOA PDFDOI

Recent grants

• EAGER: Fe/Mn-Containing Perovskite Oxides Promoted by Alkali Metal Molybdates for Chemical-Looping Catalysis – Thin-Film Preparation and Surface Characterization

  NSF · $300k · 2021–2024

• CAREER:Bi-Functional Redox Materials with Facilitated Oxygen Transport for Catalytic Conditioning of Biomass-Derived Syngas

  NSF · $417k · 2013–2018

• UNS: Collaborative Research: Multiple-Scale Investigation of Chemical Looping with Oxygen Carrier Uncoupling

  NSF · $369k · 2015–2020

• NSF-BSF and Manufacturing USA: Lattice Oxygen Assisted Methane Activation for Modular Production of Fischer-Tropsch Ready Syngas

  NSF · $305k · 2019–2025

• SusChEM: Investigation of a Core-Shell Redox Catalyst Platform for Oxidative Dehydrogenation of Ethane

  NSF · $554k · 2016–2021

Frequent coauthors

• Luke Neal

  North Carolina State University

  34 shared

• Yunfei Gao

  29 shared

• Xijun Wang

  Northwestern University

  25 shared

• Vasudev Haribal

  20 shared

• Junchen Liu

  University of International Business and Economics

  14 shared

• Ryan B. Dudek

  14 shared

• Henri Dou

  14 shared

• Jixin Jiang

  13 shared

Labs

• Li Research GroupPI

  Learn more about the current and former members of the Li Research Group at NC State, including academic backgrounds and contact information.

Education

• Ph.D., Chemical Engineering

  University of North Carolina at Chapel Hill

  2008

• M.S., Chemical Engineering

  University of North Carolina at Chapel Hill

  2003

• B.S., Chemical Engineering

  University of Science and Technology of China

  2001

Awards & honors

• Thomas M. Clausi Distinguished Professor in Chemical Enginee…