Continuous Synthesis of Optimized Ni₃(HITP)₂ With Broad Spectrum of Morphologies via Automated Microfluidic Ammonia...

The morphology of metal-organic frameworks (MOFs) critically governs their electronic, catalytic, and transport performance. However, continuous synthesis of morphology-tunable MOFs remains challenging because scaffold formation is influenced by and highly sensitive to subtle reaction condition variations, involving temperature, concentration, mixing rate, and pH. Here, we present a programmable reactor for iterative synthesis of MOFs via Microfluidics (PRISMM) that enables precise and continuous synthesis of Ni₃(HITP)₂ and Pt-decorated Ni₃(HITP)₂ with a broad spectrum of morphologies, ranging from disordered aggregates to well-defined nanosheets, thereby allowing a wide distribution of porosity. By independently regulating ammonia permeation through microfluidic chips and dynamically adjusting synthesis parameters, this platform achieves fine control over ligand deprotonation kinetics and nucleation in a continuous and reproducible manner. The resulting Ni₃(HITP)₂ exhibits optimized morphology and enhanced porosity, while incorporation of platinum maximizes Pt accessibility and exposure, facilitates rapid mass transfer, and improves active-site utilization. In ammonia borane dehydrogenation, Pt@Ni₃(HITP)₂ delivers 3 equivalents of hydrogen with over 99% purity, yielding a turnover frequency of 2323 min^-1. This work establishes an automated pathway for MOF morphology manipulation, thereby demonstrating the strong potential of programmable microfluidic synthesis for morphology-directed design of MOFs in energy, catalytic, and broader applications.