Technologies such as batteries, biomaterials, and heterogeneous catalysts have functions that are defined by mixtures of molecular and mesoscale components. As yet, this multi-length scale complexity cannot be fully captured by atomistic simulations, and the design of such materials from first principles is still rare 1-5. Likewise, experimental complexity scales exponentially with the number of variables, restricting most searches to narrow areas of materials space. Robots can assist in experimental searches 6-14 but their widespread adoption in materials research is challenging because of the diversity of sample types, operations, instruments and measurements that is required. Here we use a mobile robot to search for improved photocatalysts for hydrogen production from water 15. The robot operated autonomously over 8 days, performing 688 experiments within a 10-variable experimental space, driven by a batched Bayesian search algorithm 16-18. This autonomous search identified photocatalyst mixtures that were six times more active than the initial formulations, selecting beneficial components and deselecting negative ones. Our strategy uses a dexterous 19,20 free-roaming robot 21-24 , automating the researcher rather than the instruments. This modular approach could be deployed in conventional laboratories for a range of research problems beyond photocatalysis. Leverhulme Research Centre for Functional Materials Design, the Engineering and Physical Sciences Research Council (EPSRC) (EP/N004884/1), the Newton Fund (EP/R003580/1), and CSols Ltd. X.W. and Y.B. thank the China Scholarship Council for a Ph.D. studentship. We thank KUKA Robotics for help with gripper design and initial implementation of the robot. Author contributions. B.B. developed the workflow, developed and implemented the robot positioning approach, wrote the control software, designed the bespoke photocatalysis station, and carried out experiments. P.M.M. and V.V.G. developed the optimiser and its interface to the control software. X.L. advised on the photocatalysis workflow. C.M.A., Y.B. and X.L. synthesized materials. Y.B. performed kinetic photocatalysis experiments. X.W. performed NMR analysis and synthesized materials. B.L. carried out initial scavenger screening. R.C. and N.R. helped to build the bespoke stations in the workflow. B.H. analysed the robustness of the system, assisted with the development of control software, and operated the workflow during some experiments. B.A. helped to supervise the automation work. R.S.S. helped to supervise the photocatalysis work. A.I.C. conceived the idea, set up the five hypotheses with BB, and coordinated the research team. Data was interpreted by all authors and the manuscript was prepared by A.I.

b S Supporting InformationT he porous materials with extraordinarily high surface area have attracted enormous scientific attention due to their diverse potential applications in separation, 1 heterogeneous catalysis, 2 and gas storage. 3 During the last few decades, the surge to develop such useful materials has led scientists to produce a number of novel porous materials such as metal organic frameworks (MOFs), 4 covalent organic frameworks (COFs), 5 porous organic cages, 6 and microporous organic polymers (MOPs), 7 in addition to traditional porous materials such as zeolites and activated carbon etc. Among these porous materials, MOPs have attracted a particular attention due to their unique properties such as large surface area, low skeletal density and high chemical stability. "Davankov resins", that is, styrenetype polymers hypercrosslinked by FriedelÀCrafts reaction, 8 are one of the earliest types of MOPs and have been studied extensively, coming into industrial practice at the end of 1990s, however, the releasing hydrogen halide as byproduct is detrimental and hard to tackle. 3d,9 Hyper-cross-linked polypyrrole or polyaminobenzene or aminobenzene represent another kind of pioneering MOPs. 10 These two synthesis method can only be adapted to very limited monomers. Very recently, various other new kinds of MOPs have been developed, based on several types of reaction, such as polymers of intrinsic microporosity (PIMs) with dioxane unit, 3b microporous polymers such as conjugated microporous polymers (CMPs) 11 and porous aromatic frameworks (PAFs) 12 by various cross-coupling reactions of aromatic compound. MOPs were also formed by trimerizations of ethynyl 13 or nitrile groups, 14 by amide or imide or imine formation, 15 and via "click" chemistry. 16 All of these approaches have aimed to develop new microporous organic materials with higher surface areas and controlled pore sizes and functions. However, the transition metal catalysts or noble metal catalysts used for synthesis of CMPs, PAFs, and some other MOPs are expensive and rare. It is often also complicated to synthesize the monomers which must bear halogen, 11a ethynyl 17 or stereocontrolled structures such as spirocyclic monomers 17,18 used in MOPs. Hence, the sustainable mass production of MOPs is an unanswered challenge.In this report, we propose a new strategy, which involves "knitting" rigid building blocks with an external cross-linker. We used a simple one-step FriedelÀCrafts reaction of a low-cost cross-linker with ordinary, low functionality aromatic compounds to produce cost-effective microporous polymers with very high surface areas and the only byproduct was methanol. In this one-step cross-linking approach, formaldehyde dimethyl acetal (FDA) was used as an external cross-linker to react with various aromatic monomers (Scheme 1, parts aÀc). Typically, the monomer (e.g., benzene, 0.02 mol, 1.56 g), cross-linker (FDA, 0.06 mol, 4.56 g) and the catalyst (FeCl 3 , 0.06 mol, 9.75 g) were dissolved in 1,2-dichloroethane (DCE, 20 mL) and heate...

Aromatic heterocyclic microporous polymers with high surface areas are obtained by directly crosslinking of the heterocyclic monomers under mild conditions. Owing to the narrow pore system and the heteroatom-rich pore surface, these networks exhibit high CO(2) adsorption capacity and selectivity. At 273 K, the CO(2)/N(2) selectivity of Py-1 is about 117, which is among the highest the reported microporous materials.

Covalent triazine frameworks (CTFs) with aromatic triazine linkages have recently received increasing interest for various applications because of their rich nitrogen content and high chemical stability. Owing to the strong aromatic C=N bond and high chemical stability, only a few CTFs are crystalline, and most CTFs are amorphous. Herein we report a new general strategy to give highly crystalline CTFs by in situ formation of aldehyde monomers through the controlled oxidation of alcohols. This general strategy allows a series of crystalline CTFs with different monomers to be prepared, which are shown to have higher thermal stability and enhanced performance in photocatalysis as compared with the less crystalline or amorphous CTFs. This open-system approach is very simple and convenient, which presents a potential pathway to large-scale industrial production of crystalline CTFs.

Highly dispersed palladium chloride catalysts locked in triphenylphosphine-functionalized knitting aryl network polymers (KAPs) are developed and exhibit excellent activity under mild conditions in the Suzuki-Miyaura cross-coupling reactions of aryl chlorides in aqueous media. This work highlights that the microporous polymers not only play the role of support materials, but also protect the Pd species from aggregation and precipitation, hence, positively effect the catalysis activity.